@proceedings {931, title = {Analysis by Citizen Scientists of Doppler Radio Observations of the April, 2024 Solar Eclipse}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI community (Ham Radio Science Citizen Investigation) has analyzed high frequency radio observations of the total solar eclipse of April 8, 2024 and found interesting correlations. Nearly fifty ham radio operators recorded over 200 Doppler time series of the national time standard transmitters WWV in Colorado and CHU in Canada using specialized GRAPE (Great Radio Amateur Propagation Experiment) receivers. These observations are archived at the Personal Space Weather Station website, and cover ten frequencies from 0.6 to 25 MHz. There were over sixty different paths from transmitter to receiver at various angles across and along the path of totality from Texas to Maine. For each observation six citizen scientists collected demographic data, found distances and midpoints (where radio signals are reflected from the ionosphere), noted local eclipse information, measured the maximum Doppler shifts, counted multi-path signals, and judged the symmetry of the S-shaped Doppler curves over ingress and egress time periods. We found that the Doppler shifts depend mostly on the Sun{\textquoteright}s obscuration at the midpoint, but also on the carrier frequency and the distance between the transmitter and the receiver. At closer distances a radio wave measured a greater change in the path length as the bottom of the ionosphere retreated skyward and then returned as the Moon uncovered the Sun. \ 

}, author = {Mary Lou West and Nathaniel Frissell and Gary Mikitin and Gregory Popelas and Ronald Wilcox and McKenzie Denton and Robert Spalletta and William Engelke and Gwyn Griffiths and Steve Cerwin} } @proceedings {932, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The objective of our research is to use narrowband linear audio pulses, which are sensitive to time displacement, and transmit them through High Frequency (HF) commercial off-the-shelf (COTS) single-sideband (SSB) amateur radios to measure changes in ionospheric reflection heights, specifically during a solar eclipse. This will be accomplished and automated using programming techniques learned in the Digital Signal Processing course at the University of Scranton, where the primary objective is to use TDOA (Time Difference of Arrival), a technique that measures the time displacement of single/multiple paths as they reach a receiving station. These TDOA values will be manipulated using a virtual height model that will yield different values of ionospheric layer heights based on the locations of the receiving and transmitting stations. During the October 2023 and April 2024 solar eclipses, WA5FRF transmitted a series of linear audio pulses (chirps) every 10{\textendash}15 minutes to various receiving stations on the 5, 7, and 14 MHz amateur radio bands. Received signals were squared and filtered to detect the waveform envelope. Correlation with a matched signal was then used to identify the start time of each chirp, after which a Fast Fourier Transform (FFT) was used to identify the beat-note frequency generated by multipath propagation. The October 2023 eclipse automated analysis shows that the F region reflection point was raised from 262.5 km at 17:00 UTC to 300 km at eclipse maximum at 17:30 UTC. The April 2024 eclipse analysis shows no real maximum reflection point; however, it does indicate an increase in layer height following maximum obscuration at 18:30 UTC. Both analyses are in good agreement with the hmf2 observations of the Austin Ionosonde. The intended purpose was to monitor multipath interference for 1{\textendash}2 hops off of the F2 layer; however, recent developments in this automated process yield additional data for other modes.

}, author = {Alexandros Papadopoulo and Gerard Piccini and Nathaniel Frissell and Steve Cerwin and Jesse McMahan and Paul Bilberry and Blackshear Samuel and Aidan Montaigne and Kristina Collins and Robert Spalletta} } @proceedings {960, title = {Are Weak Type II Radio Bursts Associated with Shocks Driven by Coronal Mass Ejections?}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Type II radio bursts are a type of slow-drifting solar radio bursts, usually understood as radio signatures from shocks driven by coronal mass ejections (CMEs).\  Most previous studies on type II radio burst have focused on strong and bright type IIs, which, when imaged, have been often found to be associated with CME-driven shocks, although a few exceptions have also been reported. It remains an outstanding question whether such an association also holds for very weak type II radio bursts. Taking advantage of the imaging spectroscopy capabilities of the Owens Valley Radio Observatory{\textquoteright}s Long Wavelength Array (OVRO-LWA) with an extremely high sensitivity, we identified several weaker type II radio burst events in 15{\textendash}88 MHz, and then analyzed them using radio interferometric imaging as a function of time and frequency. Weak type II radio bursts were categorized as being less than 10 minutes in total duration with low flux (\<10 s.f.u). We located the radio emission source and characterized their shape, brightness, and spatial-temporal variation. Then, using white light and multi-band extreme ultraviolet imaging observations, we tracked their possible solar drivers. We found that some weak type II radio burst events were not associated with a typical white light CME, but with a small scale coronal disturbance within a coronal streamer. For other type IIs, we could not find any visible activity from EUV and white light. All weak type IIs do not show a clear shock front counterpart. We discuss implications of our findings in understanding the formation of type II radio bursts.

}, author = {KresUranNu Baylor and Peijin Zhan and Bin Chen} } @proceedings {949, title = {Climatology of Large-Scale Traveling Ionospheric Disturbances Observed with 14 MHz Amateur Radio Using a Novel Automated Detection Technique}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present a multi-year climatology of Large Scale Traveling Ionospheric Disturbance (LSTID) period oscillations observed using 14 MHz amateur (ham) radio data. Traveling ionospheric disturbances (TIDs) are quasi periodic electron density perturbations in the F region ionosphere that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. These are seen, in daytime, as variations in contact ranges in 14 MHz amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet), the Reverse Beacon Network (RBN), and PSKReporter. A new deterministic and fully automated method was developed for identifying and quantifying these disturbances. This technique, which filters for TID wave periods between 1 and 5 hours and curve fits a sinusoidal function to the first hop skip-distance edge of observed communication ranges, provides both TID amplitudes and periods. In this study, we present full year climatologies of LSTID events over the continental United States (CONUS) using RBN, WSPRNet, and PSK observations from 2016- 2021. Results are organized as a function wave period, amplitude, and season. We find that LSTIDs increase in winter and decline during the fall and spring, with slight enhancements in the summer and occasional brief declines in LSTID winter activity. This seasonal pattern shows consistency with previous studies and observations of LSTIDs and medium scale TIDs that suggests this behavior may be associated with neutral wind filtering in the middle atmosphere, sudden stratospheric warming (SSW) events, and multi-step vertical coupling (MSVC) processes. MSVC is a process where gravity waves (GWs) from the lower neutral atmosphere propagate upwards, break, and produce new, higher-order GWs in the thermosphere and TIDs in the ionosphere.

}, author = {Diego Sanchez and Nathaniel Frissell and Mary Lou West and V. Lynn Harvey and Sharon Vadas and Erich Becker and Gareth Perry and William Engelke and Nicholas Callahan and Philip Erickson} } @proceedings {927, title = {EZIE-Mag: A low cost, science quality, magnetometer suite enabling global coverage}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

EZIE-Mag suite is an ultra-low cost, science quality measurements that enable the global observational coverage that is required to produce space weather nowcasting and forecasting. Industry have developed solutions that allow a low cost solution. We show the hardware solution, the OS, the post-processing solution, and the educational package.

}, author = {Jesper Gjerloev and R. Barnes and E. Adebayo and L. Kepko and T. Cline and N. Mosavi-Hoyer and J. Leibert and L. Regoli and M. Freil and D. Oztruk and A. Cohen and J. Fitzer} } @proceedings {934, title = {The HamSCI Book Club}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

\ We will discuss several radio-related works of English literature: \ Romeo \& Juliet\ romeo-and-juliet_PDF_FolgerShakespeare.pdf\ and Code Poems\ Weiner_Hannah_Code_Poems.pdf

}, author = {David Kazdan and Kristina Collins and Leah Davydov} } @proceedings {928, title = {HamSCI in OpenSpace: Toward Unified Visualizations of Geospace Data}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

As HamSCI efforts developing the PSWS network continue, we amass stations and data that can help fill in the gaps in our understanding of the geospace system. However, the counterintuitive scales of the geospace system present visualization challenges, and demand flexible and intuitive tools that can showcase data and simulations over a range of spatial and temporal scales with appropriate fidelity. OpenSpace is open-source interactive data visualization software designed to visualize the entire known universe and portray our ongoing efforts to investigate the cosmos. Designed for use in planetarium domes, it can also be deployed on desktop computers, and is well-supported by a vibrant open-source development community of over twenty years. In this talk, I{\textquoteright}ll demonstrate how OpenSpace can be used as a visualization platform for HamSCI work and related data. I{\textquoteright}ll also discuss the potential for VR integration and spatialized sonification and audification in OpenSpace.

}, author = {Kristina Collins} } @proceedings {929, title = {HamSCI Solar Eclipse QSO Party (SEQP): Observations and Modeling on Ionospheric Effects}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

This study investigates the ionospheric changes during the solar eclipse of April 2024 using data from the HamSCI Solar Eclipse QSO Party (SEQP). SEQP collected radio communication data reported by ham radio operators and global automated receiving networks (e.g., WSPRNet, the Reverse Beacon Network, and PSKReporter). The datasets include radio communications at multiple frequencies in the high frequency (HF) and very high frequency (VHF) bands. Thousands of ham radio operators across the contiguous United States (CONUS) and around the globe contributed to the observations with unprecedented temporal, spatial, and spectral coverage. SEQP datasets are used to infer ionospheric state before, during, and after the solar eclipse. We use the ham radio datasets along with PHaRLAP raytrace modeling to infer the ionospheric response of the solar eclipse and also evaluate the outputs of the physics-based model SAMI3 for the eclipse ionosphere. Our findings suggest that the solar eclipse increased the range of radio communications at lower HF band (3.5, 7, 10 MHz), but decreased the longer range communications at higher HF band (21, 24, 28 MHz). Ham radio datasets from stations continually operated during the eclipse show an earlier opening of radio links between the US and Europe on the eclipse day. We are conducting modeling studies to understand the causes of changes in ham radio observations and to examine the potential combined effect of the sunset terminator and eclipse shadow during the later phase of the eclipse.

}, author = {Kuldeep Pandey and Gareth Perry and Nathaniel Frissell and Travis Atkinson and William Engelke and Joseph Huba and Mary Lou West and Philip Gladstone and Cameron Cushing and McKenzie Denton and Edward Efchak and Gary Mikitin and H. Ward Silver} } @proceedings {967, title = {Radio Wave Propagation and Antenna Fundamentals}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {
This tutorial gives a basic overview of radio propagation and the fundamentals of antennas. Topics include
The Nature of Radio Waves, Dipole Antenna Characteristics, Line of Sight Propagation, Diffraction and Multipath Interference, What a BALUN does, The Isotropic Antenna and Concept of Gain, Examples of Gain Producing Antennas and How They Work, Transmission Line Basics, and Selected Antenna Stories.\ 
}, author = {Steve Cerwin} } @proceedings {930, title = {The Solar Eclipse Inverse Problem}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI Personal Space Weather Station (PSWS) is a distributed network that includes magnetometers and high frequency receivers. The Great Radio Amateur Propagation Experiment (GRAPE) is a collection of PSWS receivers that record Doppler shift from national time standard signals. The Grape project includes Grape 1 receivers recording Doppler and spectral data as well as the upgraded Grape 2 three channel receivers and the multi-channel WSPR (Weak Signal Propagation Reporter) Grapes. The network collected data during the 2023 and 2024 solar eclipses on frequencies ranging from 2.5 to 20 MHz. The recorded Doppler shift indicates a change in signal path caused when the signal passes through the ionospheric layers in the Earth{\textquoteright}s atmosphere. Due to the scale and variability of the ionosphere, these measurements are sparse and are not accompanied by a known forward model. The reconstruction of eclipse period ionospheric behavior can therefore be viewed as a mathematical inverse problem. We explore various mathematical techniques and algorithms that could be used to solve the inverse problem and model the real time ionospheric behavior.

}, author = {Rachel Boedicker and Nathaniel Frissell and John Gibbons and Kristina Collins and David Kazdan} } @proceedings {952, title = {Why you should attend the Youth on the Air camp}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Why we\ believe every young ham radio operator, aged 15-25{\textemdash}whether you{\textquoteright}re a seasoned pro or newly licensed{\textemdash}should attend YOTA camp

}, author = {Katherine Campbell and Jack Roberts} } @proceedings {858, title = {Analysis of the HamSCI Solar Eclipse High Frequency Time Difference of Arrival Experiment Observations Using Automated Techniques}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The objective of our research is to analyze the effects of a solar eclipse on High Frequency (HF) radio by extracting the time difference of arrival (TDOA) due to multiple ionospheric paths of ~3 kHz bandwidth chirp signals sent and received with unmodified commercial off-the-shelf (COTS) single sideband (SSB) amateur radio transceivers. We use programming techniques learned in the Digital Signal Processing course at The University of Scranton in the Python language to automate this process. On the day of the 14 October 2023 eclipse in Texas, WA5FRF transmitted a series of chirps every 15 minutes to receiving stations N5DUP and AB5YO on 5.3 MHz and 7.2 MHz. Received signals were digitized, then squared and low-pass filtered to detect the waveform envelope. Correlation with a matched signal is then used to identify the start time of each chirp, after which a Fast Fourier Transform (FFT) is used to identify the beat-frequency (and TDOA value) generated by the multipath propagation. This TDOA value is then used to compute an ionospheric reflection height. On the WA5FRF-N5DUP path, this analysis shows that the F region reflection point raised from 262.5 km at 17:00 UTC to 300 km at eclipse maximum at 17:30 UTC and then returned to approximately 280 km at 18:00 UTC. This result is in good agreement with the hmF2 observations of the Austin ionosonde.

}, author = {Alexandros Papadopoulos and Gerrard Piccini and Thomas Pisano and Nicholas Guerra and Matthew Felicia and Evan Hromisin and Aidan Montare and Kristina Collins and Paul Bilberry and Samuel Blackshear and Steve Cerwin and Nathaniel A. Frissell} } @proceedings {820, title = {Citizen Science: Development of a Low-Cost Magnetometer System for a Coordinated Space Weather Monitoring}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of ~3 nT at a 1 Hz sample rate. Crowd-sourced data from the PSWS systems will be collected into a central archive for the purpose of public access and analyzation along with space weather research. Ultimately, data from the PSWS network will combine the magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large scale current systems and ionospheric disturbances and events due to drivers from space and the atmosphere alike. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is entirely satisfactory for scientific investigations.

}, author = {Joseph Visone and Hyomin Kim and David Witten and Julius Madey and Nathaniel A. Frissell and John Gibbons and William D. Engelke and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @article {913, title = {Citizen science: Development of a low-cost magnetometer system for a coordinated space weather monitoring}, journal = {HardwareX}, volume = {20}, year = {2024}, month = {Jan-12-2024}, pages = {e00580}, abstract = {
As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of\ 3 nT at a 1 Hz sample rate. The measurement range of the sensor is\ \ nT) and is valid over a temperature range of -40 {\textdegree}C to +85 {\textdegree}C. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3{\textendash}30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is very adequate for scientific investigations.
}, keywords = {magnetometer}, issn = {24680672}, doi = {10.1016/j.ohx.2024.e00580}, url = {https://www.sciencedirect.com/science/article/pii/S2468067224000749}, author = {Kim, Hyomin and Witten, David and Madey, Julius and Frissell, Nathaniel and Gibbons, John and Engelke, William and Liddle, Anderson and Muscolino, Nicholas and Visone, Joseph and Cao, Zhaoshu} } @proceedings {835, title = {Comparative Analysis of Medium Scale Travelling Ionospheric Disturbances: Grape PSWS vs. SuperDARN}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are periodic fluctuations in ionospheric electron density associated with atmospheric gravity waves. They are characterized by wavelengths of 50-500 kilometers and periods of 15-60 minutes. This study presents initial findings from a comparative analysis of MSTID observations sourced from two distinct systems: the Super Dual Auroral Radar Network (SuperDARN) and the Grape Personal Space Weather Station (PSWS). The Grape PSWS, developed by the Ham Radio Science Citizen Investigation (HamSCI), is a small ground-based remote sensing device aimed at monitoring space weather parameters, including MSTIDs. It achieves this by monitoring a 10 MHz transmission from WWV, a National Institute of Standards and Technology (NIST) time standard station located near Fort Collins, Colorado, USA. In contrast, SuperDARN comprises a global network of high-frequency radars that offer extensive coverage of ionospheric plasma motion. This comparative investigation focuses on aligning MSTID observations obtained from Grape PSWS data with SuperDARN radar data. By investigating datasets from both platforms, these findings serve as initial results for an ongoing investigation of MSTIDs, laying the groundwork for a comprehensive understanding of their dynamics and impacts on ionospheric variability and space weather.

}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Bharat Kunduri and J. Michael Ruohoniemi and Joseph Baker and William Liles and John Gibbons and Kristina Collins and David Kazdan and Rachel Boedicker} } @proceedings {860, title = {Construction of a Table-Top Antenna Range for Learning Electromagnetics Concepts}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Antenna construction and measurement provide an effective method of teaching electromagnetic and antenna concepts, including polarization, gain, directivity, and reflection. During the Spring 2024 semester, the University of Scranton EE 448 Electromagnetics II class is undertaking a project to build a table-top antenna range at 2450 MHz (λ = 12 cm). The table top range will give hands-on visual and intuitive reinforcement of abstract concepts covered mathematically in the course textbook. This frequency was chosen due to the convenient size of antennas and the fact that the antennas will be usable in the 2.4 GHz Industrial, Scientific, and Medical (ISM) and amateur bands. ISM band applications include WiFi, Bluetooth, RFID, NFC, and more. In this presentation and poster, we demonstrate three types of antennas the class has built so far: dipoles, dipoles with corner reflectors, and loops over ground planes. We also demonstrate the use of a NanoVNA to measure antenna properties, as well as show ideas for future projects.

}, author = {Augustine Brapoh and Matthew Dittmar and Aidan Szabo and Robert Troy and Nathaniel Frissell and Stephen A. Cerwin} } @proceedings {859, title = {Estimation of Ionospheric Layer Height by Measuring the Time Difference of Arrival (TDOA) Between 1 and 2 Hop Propagation Modes. 2023 Annular Eclipse Observations}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

A HamSCI science objective for the 2023 and 2024 eclipses is to use amateur radio stations to measure how the ionosphere changes with eclipse passage. Of particular interest is the change in effective ionization layer height caused by the momentary blockage of solar radiation. Layer height between two stations can be deduced from a Time of Flight (TOF) measurement but doing so requires complexity beyond the capability of most amateur radio stations. Particularly difficult requirements are precision absolute time references for both stations and calibration of the lengthy time delays incurred in modern DSP based transceivers. A simpler method that can be just as effective is to measure the Time Difference of Arrival (TDOA) between the 1- and 2- hop modes over paths and frequencies that support both modes. The 1-hop mode is shorter and arrives first, followed by the longer 2-hop mode. Geometric models based on virtual height or refractive ray tracing can be used to mathematically relate 1-2 hop TDOA to layer height. The measurement can be implemented by transmitting audio signals that are sensitive to a time delay when summed together, as happens in the receiver during simultaneous 1 and 2 hop propagation. Suitable audio waveforms include a 1-cycle audio burst, audio chirps of controlled sweep rate, and a pseudorandom noise burst. The TDOA measurement using the short pulses is performed by directly measuring the time difference between the two received pulses. The summation of a chirp waveform with a delayed copy of itself produces a beat note equal to the product of the sweep rate and the time delay that can be used to calculate TDOA. The TDOA can be extracted from both the PN bursts and chirps through an autocorrelation technique. The audio signals can simply be fed to the microphone input and recovered from the speaker output of ordinary SSB amateur radio equipment using audio .wav programs. This paper gives details of the method and of on-air experiments both before and during the 2023 Annular Eclipse.

}, author = {Steven A. Cerwin and Paul Bilberry and Sam Blackshear and Jesse T. McMahan and Kristina V. Collins and Nathaniel A. Frissell} } @proceedings {824, title = {Initial Review of the October 2023 Grape Eclipse Data}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The Great Radio Amateur Propagation Experiment (GRAPE) is a network of Doppler receivers that function as a distributed multi-static radar. The Grape network received 10 MHz doppler data from the NIST time and frequency station WWV in Fort Collins, CO during the 2023 October annular eclipse. Grape receivers in the network recorded a spectrum of Doppler shift data of the signals after they passed through the eclipse modified ionosphere. An updated version of the receiver will\  be deployed to expand the network and collect similar data during the 2024 April total solar eclipse. We present initial data and results of the 2023 eclipse and discuss the upcoming eclipse.

}, author = {Rachel Boedicker and Nathaniel A. Frissell and John Gibbons and Kristina Collins} } @proceedings {873, title = {Reexamining the Characteristics of Flare-Driven Doppler Flash using multipoint HF Observations}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Sudden enhancement in the ionospheric electron density following a solar flare causes disruption in the transionospheric high frequency (HF: 3-30 MHz) communications, commonly referred to as Shortwave Fadeout (SWF). This disruption is also recorded as a sudden enhancement in Doppler frequency in the received HF signal, referred to as Doppler Flash. This phenomenon was recorded and reported by the SuperDARN HF radar network. Previous investigations have suggested that among various phases of flare-driven SWFs observed by HF radars Doppler Flash is the first to observe, and there are no significant trends in Doppler Flash with location, operating frequency, or flare intensity. Recent development showed that Doppler observations from the distributed HamSCI Personal Space Weather Station (PSWS) can provide insight into the physics behind changes in phase path length of the trans ionospheric radio signals. Unlike SuperDARN, HamSCI PSWS can record the full phase of the Doppler Flash, provide an edge to revisit the characterization study and compare with existing dataset. In this study, we demonstrate how HamSCI observations can be used to infer flare-driven changes in ionospheric properties. We found: (1) HamSCI PSWS has higher dynamic range than SuperDARN during flare making it less susceptible to SWF, thus it can record the full Doppler Flash; (2) data from HamSCI PSWS shows a strong function trend with flare strength, operating frequency, and location on the Earth; and (3) HF rays traveling longer distances experienced statistically higher Doppler. We understand that, while instantaneous Doppler realized by the HF signal is proportional to the rate of change in solar irradiance, the total Doppler realized is proportional to the total flare-deposited energy in the ionosphere.

}, author = {Shibaji Chakraborty and Kristina V. Collins and Nathaniel A. Frissell and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {850, title = {Trial of applying PHaRLAP raytracing to reproduce Ham spot data}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

HamSCI is one of the NASA{\textquoteright}s official citizen science projects. HamSCI\ spots database, which is from Reverse Beacon Network (RBN) and Weak Signal Propagation Reporter Network (WSPRNet), is of interest. Information of date, time, frequency, latitude, and longitude of transmitter and receiver are used. PHaRLAP is a raytracing tool that can trace the HF radio wave in 2D and 3D. We use the IRI model to generate the required ionospheric information. We employ the PHaRLAP\ to reproduce the ham spots database by launching the HF radio wave from the transmitter, of which its location is obtained from the HamSCI\ spots database. Then, we trace the O-mode propagation of the wave. The wave arrival latitude and longitude are then mapped into a grid based on the Amateur Radio Maidenhead Grid. Finally, we compare the raytracing-based arrival grid with the HamSCI\ arrival grid. The results, under the assumption of 1-hop propagation, show that the PHaRLAP\ raytracing can reproduce the HamSCI\ spots database well.

}, author = {Kornyanat Hozumi and Nathaniel A. Frissell and Min-Yang Chou and Gwyn Griffiths and William D. Engelke and Jia Yue and Shing Fung and Masha Kuznetsova} } @proceedings {875, title = {Wave Activity in Thermospheric Vertical Winds and Temperatures at Subauroral Latitudes}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The need for high precision measurements of vertical winds with uncertainties less than 3-5 m/s and a temporal cadence of 1-2 min has made it exceedingly difficult to study the response of the thermosphere to gravity wave activity.\  Herein we present subauroral, midlatitude thermospheric wave measurements of 630 nm OI emission from a 15 cm narrow field Fabry Perot Interferometer, named the Hot Oxygen Doppler Imager (HODI).\  These measurements of temperature and vertical wind velocities are from a first light campaign at Jenny Jump Observatory (40.9 N, 74.9 W) located in northwestern New Jersey. The heightened sensitivity of HODI enables analysis of gravity wave behavior with uncertainties of 3-5 m/s for vertical wind speeds and 10-15 K for temperatures for two-minute exposures. Data was collected during periods of geomagnetically quiet and active conditions, and apparent wave structures were seen during both conditions.\  One detailed observation, taken the night of July 25, 2022, enabled the ~90-deg phase shift between vertical winds and temperatures to be inferred, as per standard gravity wave polarization relations with viscous dissipation.\  However, most other observations found to have little correlation between the temperature and vertical winds, which we speculate may be a result of the propagation and interaction of multiple wave events. Traveling ionospheric disturbances (TIDs) are often described as the ionospheric signature of the passage of gravity waves, and we provide comparisons of select wave events to medium scale TIDs using differential total electron count (TEC) maps.

}, author = {Anneliese Schmidt and John W. Meriwether and Matthew B. Cooper and Andrew J. Gerrard and Lindsay V. Goodwin and Shun-Rong Zhang and Gilbert Jeffer and Chris Callie} } @proceedings {750, title = {AC Motor Drive With Power Factor Correction Using Arduino}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

By using various electrical and computer engineering concepts, this project incorporates different sectors explored through current curriculum. By implementing these concepts, a fully functioning AC motor controller will be designed. The project is split into 5 groups: AC to DC power conversion, DC to AC power control, power factor correction, capacitor bank control, and Arduino interfacing, all working on separate critical components for the motor controller. As this is currently a work in progress, actual conclusions cannot be made, but speculation based on calculations is available.

}, author = {Christian D. Chakiris and Robert C. Brudnicki and Robert D. Troy and John A. Nelson and Matthew K. Dittmar and Augustine D. Brapoh Jr. and Milton Andrade and Sade Lugo and Aidan T. Szabo and Kenneth Dudeck} } @proceedings {691, title = {Climatology of Ionospheric Variability with MSTID Periods Observed Using Grape v1 HF Doppler Receivers}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Veronica Romanek and Nathaniel Frissell and Kristina Collins and John Gibbons and David Kazdan and William Liles} } @article {797, title = {Crowdsourced Doppler measurements of time standard stations demonstrating ionospheric variability}, journal = {Earth System Science Data}, volume = {15}, year = {2023}, month = {Jan-01-2023}, pages = {1403 - 1418}, abstract = {

Ionospheric variability produces measurable effects in Doppler shift of HF (high-frequency, 3{\textendash}30 MHz) skywave signals. These effects are straightforward to measure with low-cost equipment and are conducive to citizen science campaigns. The low-cost Personal Space Weather Station (PSWS) network is a modular network of community-maintained, open-source receivers, which measure Doppler shift in the precise carrier signals of time standard stations. The primary goal of this paper is to explain the types of measurements this instrument can make and some of its use cases, demonstrating its role as the building block for a large-scale ionospheric and HF propagation measurement network which complements existing professional networks. Here, data from the PSWS network are presented for a period of time spanning late 2019 to early 2022. Software tools for the visualization and analysis of this living dataset are also discussed and provided. These tools are robust to data interruptions and to the addition, removal or modification of stations, allowing both short- and long-term visualization at higher density and faster cadence than other methods. These data may be used to supplement observations made with other geospace instruments in event-based analyses, e.g., traveling ionospheric disturbances and solar flares, and to assess the accuracy of the bottomside estimates of ionospheric models by comparing the oblique paths obtained by ionospheric ray tracers with those obtained by these receivers. The data are archived at\ https://doi.org/10.5281/zenodo.6622111(Collins,\ 2022).

}, doi = {10.5194/essd-15-1403-2023}, url = {https://essd.copernicus.org/articles/15/1403/2023/https://essd.copernicus.org/articles/15/1403/2023/essd-15-1403-2023.pdf}, author = {Collins, Kristina and Gibbons, John and Frissell, Nathaniel and Montare, Aidan and Kazdan, David and Kalmbach, Darren and Swartz, David and Benedict, Robert and Romanek, Veronica and Boedicker, Rachel and Liles, William and Engelke, William and McGaw, David G. and Farmer, James and Mikitin, Gary and Hobart, Joseph and Kavanagh, George and Chakraborty, Shibaji} } @proceedings {762, title = {Development of HamSCI PSWS Ground Magnetometer and Data Visualization on the PSWS Central Website}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Hyomin Kim and Nathaniel A. Frissell and David Witten and Julius Madey and William D. Engelke and Tom Holmes and Majid Mokhtari and Scotty Cowling and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @article {801, title = {Heliophysics and amateur radio: citizen science collaborations for atmospheric, ionospheric, and space physics research and operations}, journal = {Frontiers in Astronomy and Space Sciences}, volume = {10}, year = {2023}, month = {Apr-11-2024}, abstract = {

The amateur radio community is a global, highly engaged, and technical community with an intense interest in space weather, its underlying physics, and how it impacts radio communications. The large-scale observational capabilities of distributed instrumentation fielded by amateur radio operators and radio science enthusiasts offers a tremendous opportunity to advance the fields of heliophysics, radio science, and space weather. Well-established amateur radio networks like the RBN, WSPRNet, and PSKReporter already provide rich, ever-growing, long-term data of bottomside ionospheric observations. Up-and-coming purpose-built citizen science networks, and their associated novel instruments, offer opportunities for citizen scientists, professional researchers, and industry to field networks for specific science questions and operational needs. Here, we discuss the scientific and technical capabilities of the global amateur radio community, review methods of collaboration between the amateur radio and professional scientific community, and review recent peer-reviewed studies that have made use of amateur radio data and methods. Finally, we present recommendations submitted to the U.S. National Academy of Science Decadal Survey for Solar and Space Physics (Heliophysics) 2024{\textendash}2033 for using amateur radio to further advance heliophysics and for fostering deeper collaborations between the professional science and amateur radio communities. Technical recommendations include increasing support for distributed instrumentation fielded by amateur radio operators and citizen scientists, developing novel transmissions of RF signals that can be used in citizen science experiments, developing new amateur radio modes that simultaneously allow for communications and ionospheric sounding, and formally incorporating the amateur radio community and its observational assets into the Space Weather R2O2R framework. Collaborative recommendations include allocating resources for amateur radio citizen science research projects and activities, developing amateur radio research and educational activities in collaboration with leading organizations within the amateur radio community, facilitating communication and collegiality between professional researchers and amateurs, ensuring that proposed projects are of a mutual benefit to both the professional research and amateur radio communities, and working towards diverse, equitable, and inclusive communities.

}, doi = {10.3389/fspas.2023.1184171}, url = {https://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/fullhttps://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/full}, author = {Frissell, Nathaniel A. and Ackermann, John R. and Alexander, Jesse N. and Benedict, Robert L. and Blackwell, William C. and Boedicker, Rachel K. and Cerwin, Stephen A. and Collins, Kristina V. and Cowling, Scott H. and Deacon, Chris and Diehl, Devin M. and Di Mare, Francesca and Duffy, Timothy J. and Edson, Laura Brandt and Engelke, William D. and Farmer, James O. and Frissell, Rachel M. and Gerzoff, Robert B. and Gibbons, John and Griffiths, Gwyn and Holm, Sverre and Howell, Frank M. and Kaeppler, Stephen R. and Kavanagh, George and Kazdan, David and Kim, Hyomin and Larsen, David R. and Ledvina, Vincent E. and Liles, William and Lo, Sam and Lombardi, Michael A. and MacDonald, Elizabeth A. and Madey, Julius and McDermott, Thomas C. and McGaw, David G. and McGwier, Robert W. and Mikitin, Gary A. and Miller, Ethan S. and Mitchell, Cathryn and Montare, Aidan and Nguyen, Cuong D. and Nordberg, Peter N. and Perry, Gareth W. and Piccini, Gerard N. and Pozerski, Stanley W. and Reif, Robert H. and Rizzo, Jonathan D. and Robinett, Robert S. and Romanek, Veronica I. and Sami, Simal and Sanchez, Diego F. and Sarwar, Muhammad Shaaf and Schwartz, Jay A. and Serra, H. Lawrence and Silver, H. Ward and Skov, Tamitha Mulligan and Swartz, David A. and Themens, David R. and Tholley, Francis H. and West, Mary Lou and Wilcox, Ronald C. and Witten, David and Witvliet, Ben A. and Yadav, Nisha} } @proceedings {694, title = {Measuring Daily Ionospheric Variability and the 2023 and 2024 Solar Eclipse Ionospheric Impacts Using HamSCI HF Doppler Shift Receivers}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

This project will study ionospheric variability across the continental United States (CONUS) generated by dawn/dusk transitions and two solar eclipses occurring in 2023 and 2024. Dawn and dusk produce a complex response in observed ionospheric variability that is still not completely understood. A network of Global Navigation Satellite System (GNSS) stabilized/synchronized high frequency (HF) receivers known as Grapes will be used for the study. Thirty Grape receivers will be deployed throughout North America to optimize the study of the ionospheric impacts simultaneously received from two locations. Additional stations will be funded by the HamSCI amateur radio community. This project will generate observations to answer the scientific questions: (1) How do dawn and dusk ionospheric variability vary with local time, season, latitude, longitude, frequency, distance, and direction from the transmitter? (2) Is eclipse ionospheric response symmetric with regard to the onset and recovery timing? (3) How similar is the eclipse to the daily dawn and dusk terminator passage? (4) Would multipath HF mode-splitting in the post-eclipse interval be similar to dawn events? (5) Would the response be different for two eclipses?

This project is part of the Ham Radio Science Citizen Investigation (HamSCI) program and will be open to volunteers who want to field instruments and contribute to scientific analysis and discussion. This project will also establish a new network of DASI instruments that, due to its low cost and operation by volunteers, has the potential to provide measurements for years to come. This project will support students (undergraduate, MS and Ph.D.).

}, author = {Rachel Boedicker and Nathaniel Frissell and Kristina Collins and John Gibbons and David Kazdan and Philip J. Erickson} } @proceedings {764, title = {Medium Scale Traveling Ionospheric Disturbances and their Connection to the Lower and Middle Atmosphere}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Nathaniel A. Frissell and Francis Tholley and V. Lynn Harvey and Sophie R. Phillips and Katrina Bossert and Sevag Derghazarian and Larisa Goncharenko and Richard Collins and Mary Lou West and Diego F. Sanchez and Gareth W. Perry and Robert B. Gerzoff and Philip J. Erickson and William D. Engelke and Nicholas Callahan and Lucas Underbakke and Travis Atkison and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {756, title = {A New Station for the W3USR University of Scranton Amateur Radio Club}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Tom Pisano and Nathaniel Frissell and Jeff DePolo and The W3USR University of Scranton Amateur Radio Club} } @proceedings {702, title = {The North Dakota Dual Aurora Camera Version 2.0 (NoDDAC2.0), a Platform for Citizen Science and a Use Case for Implementing Best Practices in Open Data and Collaboration}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The North Dakota Dual Aurora Camera (NoDDAC) is an interdisciplinary project created in collaboration with the University of North Dakota (UND), Live Aurora Network, and Aurorasaurus. Aurora cameras provide ground-truth visual data to aurora chasers and scientists but are sparse at midlatitudes (35-55{\textdegree}N). Deploying light-sensitive video and all-sky still cameras at these midlatitudes provides a valuable resource to aurora-chasing communities, as well as amateur radio operators in the auroral zone. In addition, NoDDAC data demonstrate scientific merit, as it can be correlated with radio and ionospheric propagation changes to investigate the connection between optical aurora and radio science. This project is unique; the practices of utilizing dual cameras with consumer-off-the-shelf equipment, emphasizing open data as a responsive community resource and promoting citizen science make NoDDAC an accessible resource benefiting multiple audiences. Since early 2021, NoDDAC has detected hundreds of auroras as well as notable events like STEVEs (Strong Thermal Emission Velocity Enhancement). NoDDAC is stationed at Martens Observatory (48.1{\textdegree}N, 97.6{\textdegree}W), which is operated by the UND Department of Physics and Astrophysics. Live Aurora Network provides weatherproof camera housings and their proprietary IPTimelapse software which allows for remote control of the cameras. This year we present NoDDAC2.0, the next evolution of NoDDAC funded by NASA{\textquoteright}s EPSCoR program. NoDDAC2.0 will upgrade the all-sky camera and feature a robust open-data platform to share aurora data with the public and scientists. We outline a strategy to increase the science utility of NoDDAC data, incorporating a citizen science project launching on the Zooniverse platform. We also present plans to integrate NoDDAC data into the AuroraX conjunction finder system so that satellite data can be easily correlated to aurora images. Most importantly, we are collaborating with the Nueta Hidatsa Sahnish College on the Fort Berthold Indian Reservation to install an independent aurora camera system in North Dakota. Not only does this represent a unique collaborative opportunity, but at a separation distance of 300 miles from Martens Observatory, this second camera will allow us to explore research questions relating to the precise location, height, and spatial extent of certain auroral phenomena.

}, author = {Timothy Young and Vincent Ledvina and Elizabeth MacDonald and Laura Brandt and Wayne Barkhouse and Alex Schultz and Cody Payne and Anne Mitchell and Kristian Haugen and Will Shearer and Kerry Hartman and Sasha Sillitti and Michael McCormack and Steve Collins} } @proceedings {766, title = {On-Air Multipath TDOA Experiments for Ionospheric Layer Height Measurements Using Amateur Radio Stations}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

}, author = {Steve Cerwin and Paul Bilberry} } @proceedings {729, title = {The potential of HamSCI Doppler Observations for inferring Solar Flare Effects on the Ionosphere}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A solar flare is a space weather event that causes a transient in the ionospheric system at sub-auroral, middle, and lower latitudes, commonly known as the solar flare effect (SFE). Sudden enhancement in high-frequency (HF) absorption is a well-known impact of solar flare-driven Short-Wave Fadeout (SWF). Less understood, is a perturbation of the radio wave frequency as it traverses the lower ionosphere in the early stages of SWF, also known as the Doppler flash. SuperDARN radar network is typically used to study the Doppler flash. Previous investigations have suggested two possible sources that might contribute to the manifestation of Doppler flash: first, enhancements of plasma density in the D and lower E-regions; second, the lowering of the reflection point in the F-region. HamSCI is a platform that publicizes and promotes scientific research and understanding through amateur radio activities in the HF band. Studies have shown that solar flare-driven HF absorption can affect amateur radio signal strength. Recent development showed that the HamSCI Doppler observations can provide insight into the physics behind changes in phase path length of the trans ionospheric radio signals. In this study, we will demonstrate how HamSCI Doppler observations can be used to infer flare-driven changes in the ionospheric properties and associated Doppler flash. Furthermore, if successful the study will also quantify Doppler flash recorded in HamSCI as a function of flare strength, flare location on the solar disk, operating frequency, and location on the Earth. Upon successful quantification of Doppler flash, we will compare its properties with previous studies that used SuperDARN observations.

}, author = {Shibaji Chakraborty and Kristina Collins} } @proceedings {745, title = {Power Factor Detection and Correction of a Variable Speed AC motor}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Christian Chakirus and Robert Brudnicki and Robert Troy and Kenneth Dudeck} } @proceedings {699, title = {Project HALO: An Effort to Provide Continuous Meteorological Observations of the April 8th, 2024 Total Solar Eclipse}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Project HALO aims to provide continuous meteorological monitoring of the total solar eclipse on April 8th, 2024. The project{\textquoteright}s preliminary goals are to determine whether or not the boundary layer temperature inversion generated by the eclipse can be considered a function of latitude. To complete this endeavor, we seek to create a network of observation teams to collect data on the day of the eclipse. We hope to provide a space for a discussion on interest, logistics, and the possibility of expanding the scope of the project to potentially include the monitoring of the solar corona, atmospheric compositional dynamics, and other topics of interest. Since the project will still be in its planning phase, not all details will be determined by the time of the conference.

}, author = {Wesley Taylor and Allison Krantz and Joshua Kinsky and Nichole Behrenhauser and Alex Colgate and Melodie Martinez-Manahan} } @proceedings {757, title = {PyLap: An Open Source Python Interface to the PHaRLAP Ionospheric Raytracing Toolkit}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

PyLap is a Python interface to the ionospheric ray tracing toolkit PHaRLAP. The software allows users to generate accurate models of the ionosphere and ray tracing to make plots of radio propagation through the ionosphere. Not only does this software look, feel, and operate very similarly to how the MATLAB interface is currently used, it is also completely free alternative to the current MATLAB interface.

}, author = {Devin Diehl and Gerard Piccini and Alexander Calderon and Joshua Vega and William Liles and Nathaniel A. Frissell} } @proceedings {687, title = {Tangerine SDR Integration Update}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

This presentation will cover the current status of FPGA firmware and module testing
on the Tangerine SDR system. The system is currently using the MAX10 Development
kit, the Tangerine receiver module and clock module, and an adaptor between the
components and the Development board. The development system used Intel Quartus
version 20.1 on Linux.

}, author = {Tom McDermott and Scotty Cowling and John Ackermann} } @proceedings {730, title = {Through a Channel Dispersively with FB Copy: An Experience of fldigi Operating Modes}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Bring a laptop with fldigi installed for the microphone/speaker soundcard
Have some small .jpg files to send.
Try different phase and frequency digital modes in noise, multipath, and dispersion, discuss the fldigi {\textquoteright}scope views.

}, author = {Kristina Collins and Rachel Boedicker and David Kazdan} } @proceedings {712, title = {Time Difference of Arrival (TDOA) Measurements on Multipath Propagation Modes to Profile Ionospheric Layer Height Changes During Solar Eclipses}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A science objective for the 2023 and 2024 eclipses is to measure how HF propagation changes with eclipse passage. Two parameters of interest are the change in effective in F2 ionization layer height caused by the momentary blockage of solar radiation and the symmetry in recovery as solar radiation returns after eclipse passage. The changes in layer height that occurred during the 2017 eclipse and that occur daily at dawn and dusk have been studied by both Doppler analyses and, in the latter case more directly by Time-of-Flight (TOF) measurements. The WWV analyses were enabled by the station{\textquoteright}s precise carrier frequency accuracy and by transmission of timing markers precisely synchronized to UTC. The objective of the proposed SEQP experiment is to acquire similar data from amateur radio stations using common amateur radio equipment and authorized frequencies. But most amateur radios possess neither the frequency stability for accurate Doppler analysis nor an easy way to time-synchronize for accurate TOF measurements. However, over propagation paths that support transmission of multiple hops, an audio chirp waveform can be transmitted to measure the Time Difference of Arrival (TDOA) between multipath modes, particularly the 1- and 2- hop modes. For a given TX-RX path, the arrival times for multiple hops from a common ionization layer are geometrically locked together by ground distance, layer height, and geometry. Therefore a 1-hop, 2-hop TDOA measurement could be used to infer effective layer height and track how it changes with time over the course of the eclipse. The method is like a conventional chirp radar technique but instead of the usual swept carrier an audio chirp is fed into the microphone input of a radio transmitter operating in voice mode. The TDOA approach eliminates the need for precise frequency and timing accuracy, allowing the use of simple amateur radio equipment. This paper presents the methodology proposed for use in the experiments, gives examples of TDOA measurements already performed using the scientific waveforms being transmitted at 8 and 48 minutes after the hour by WWV and WWVH, and discusses anticipated issues associated with the method.

}, author = {Stephen A. Cerwin} } @proceedings {759, title = {An Update on the WWV/H Modulation Test and WWV ARC}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The WWV/H Scientific Modulation Test continues after 16 months broadcasting at minute 8 on WWV and minute 48 on WWVH.\  Initial evaluation of the recordings show promise in determining time-of-flight and other characteristics.\  Efforts have started to place a KiwiSDR receiver on Kauai for an evaluation of WWVH broadcasts similar to those made of WWV.\  The WWV ARC held the Tune In: The WWV Frequency Celebration at the beginning of March to mark the 100th anniversary of WWV providing standard frequencies.\  NIST and HamSCI presented talks on March 2,\  NIST provided tours of the Boulder and WWV facilities March 3, and The Fort Collins Museum of Discovery hosted the Tune In: The WWV Frequency Celebration open house on March 4.\  Various aspects of amateur radio were showcased including traditional HF (with a station), ARISS, ARES, satellite, HamSCI, and of course a history of WWV.

}, author = {Dave Swartz and Kristina Collins} } @article {802, title = {Validating Ionospheric Models Against Technologically Relevant MetricsAbstractPlain Language SummaryKey Points}, journal = {Space Weather}, volume = {21}, year = {2023}, month = {Jan-12-2023}, abstract = {

New, open access tools have been developed to validate ionospheric models in terms of technologically relevant metrics. These are ionospheric errors on GPS 3D position, HF ham radio communications, and peak F-region density. To demonstrate these tools, we have used output from Sami is Another Model of the Ionosphere (SAMI3) driven by high-latitude electric potentials derived from Active Magnetosphere and Planetary Electrodynamics Response Experiment, covering the first available month of operation using Iridium-NEXT data (March 2019). Output of this model is now available for visualization and download via\ https://sami3.jhuapl.edu. The GPS test indicates SAMI3 reduces ionospheric errors on 3D position solutions from 1.9\ m with no model to 1.6\ m on average (maximum error: 14.2\ m without correction, 13.9\ m with correction). SAMI3 predicts 55.5\% of reported amateur radio links between 2{\textendash}30\ MHz and 500{\textendash}2,000\ km. Autoscaled and then machine learning {\textquotedblleft}cleaned{\textquotedblright} Digisonde NmF2 data indicate a 1.0\ {\texttimes}\ 1011\ el. m3\ median positive bias in SAMI3 (equivalent to a 27\% overestimation). The positive NmF2 bias is largest during the daytime, which may explain the relatively good performance in predicting HF links then. The underlying data sources and software used here are publicly available, so that interested groups may apply these tests to other models and time intervals.

}, issn = {1542-7390}, doi = {10.1029/2023SW003590}, url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023SW003590https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023SW003590https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023SW003590}, author = {Chartier, A. T. and Steele, J. and Sugar, G. and Themens, D. R. and Vines, S. K. and Huba, J. D.} } @proceedings {700, title = {Viability of Nowcasting Solar Flare-Driven Radio-Blackouts Using SuperDARN HF Radars}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The first space weather impact of a solar flare is radio blackout across the dayside of the Earth. At a delay of just 8 minutes, the arrival of enhanced X-ray and EUV radiation leads to a dramatic increase in ionization density in the lower ionosphere. Operation of HF systems are often completely suppressed due to anomalous absorption, while many RF systems suffer some degradation. While the onset of blackout is very rapid (~1-minute), the recovery takes tens of minutes to hours. Furthermore, severe solar flares can disrupt emergency HF communications that support humanitarian aid services, including amateur radio and satellite communication systems. Our current monitoring capability is based on modeling the ionospheric impacts based on GOES satellite observations of solar fluxes. We present a technique to characterize radio blackout following solar flares using HF radar. The future extension of this work is to develop an now-casting system to identify and monitor radio blackouts using HF radars currently deployed to support space science research. Networks of such radars operate continuously in the northern and southern hemisphere as part of the SuperDARN collaboration. Recent studies have shown that radio blackout (also known as shortwave fadeout) is easily detected and characterized using radar observations. We will combine real-time observations from the North American suite of SuperDARN radars to specify the occurrence of radio blackouts in near real-time.

}, author = {Shibaji Chakraborty and J. Michael Ruohoniemi and Joseph B. H. Baker} } @article {667, title = {Amateur Radio: An Integral Tool for Atmospheric, Ionospheric, and Space Physics Research and Operations}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.18632d86}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Michael Lombardi and Elizabeth MacDonald and Francesca Di Mare and Ethan S. Miller and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and David R. Themens and Mary Lou West} } @proceedings {628, title = {Climatology of Large Scale Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations of F-region ionospheric electron densities that can affect the range and quality of High Frequency (HF, 3-30 MHz) radio communications. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency radio signals propagating through the ionosphere. TIDs are of great interest scientifically because they are often associated with neutral Atmospheric Gravity Waves (AGWs) and can be used to advance understanding of atmosphere-ionosphere coupling. Large scale TIDs (LSTIDs) have periods of 30-180 min, horizontal phase velocities of 100 - 250 m/s, and horizontal wavelengths of over 1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). Current amateur radio observations are only able to detect LSTIDs. In this study, we present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, author = {Diego S. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and V. Lynn Harvey and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @article {670, title = {Fostering Collaborations with the Amateur Radio Community}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.09fe22b4}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and Timothy J. Duffy and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Elizabeth MacDonald and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and Tamitha Mulligan Skov and Mary Lou West} } @proceedings {652, title = {Geomagnetic Indices and The Ring Current}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Since the Space Age, the study of the near Earth space environment has become of great importance due to the advent of electrical systems, radio communications, and satellites which are directly affected by the state of the space environment around the Earth.\  The study of the {\textquoteleft}weather{\textquoteright} of this space environment comes in many shapes and forms but has mostly centered around the analysis and prediction of disturbances in the environment. These disturbances have been dubbed {\textquoteleft}geomagnetic storms{\textquoteright}, and their effects can range from inconsequential\  to, in the most severe cases, society altering.\  Several features of this space environment create changes at the ground level as they vary which can be measured and assigned values.\  In this poster we focus on three such values: Kp, F10.7, and Sym-H/Dst.\  The Sym-H/Dst index is of particular interest as it relates to one of the more prominent subsystems of the Earth{\textquoteright}s geospace environment, namely the ring current.

}, author = {Matthew Cooper and Andrew Gerrard} } @proceedings {646, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low Cost HamSCI Personal Space Weather Stations}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3 30 MHz) refracted radio waves. The authors present an analysis of observations of TIDs made with Ham Radio Science Citizen Investigation ( HamSCI ) Low Cost Personal Space Weather Stations (PSWS) located in Northwestern New Jersey and near Cleveland, Ohio. The TIDs were detected in the Doppler shifted carrier of the received signal from the 10 MHz WWV frequency and time standard station in Fort Collins, CO. Using a lagged cross correlation analysis, we demonstrate a method for determining TID wavelength, direction, and period using the collected WWV HF Doppler shifted data.

}, author = {Veronica Romanek and Nathaniel A. Frissell and William Liles and John Gibbons and Kristina V. Collins} } @proceedings {650, title = {Magnetosphere-Ionosphere Coupling Studies Using the PSWS Magnetometer Network}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

As part of HamSCI Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer, which measures magnetic field strength and direction, has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of ~6 nT at a 1 Hz sample rate. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that its performance is very adequate for scientific investigations.

}, author = {Hyomin Kim and Sadaf Ansari and Julius Madey and David Witten and David Larsen and Scotty Cowling and Nathaniel Frissell and James Weygand} } @proceedings {614, title = {The North Dakota Dual Aurora Camera (NoDDAC), A Student-led Citizen Science Project: Data Showcase, Future Developments, and Scientific Potential}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

The North Dakota Dual Aurora Camera (NoDDAC) is a student-led project in collaboration with the University of North Dakota (UND), Live Aurora Network, and Aurorasaurus. Aurora cameras provide ground-truth visual data to aurora chasers and scientists, but are sparse at midlatitudes. Deploying a light-sensitive video camera and allsky still camera in these areas provides a valuable resource to aurora-chasing communities, including ham radio operators in the auroral zone, and demonstrates scientific merit. For example, the analysis of rare phenomena benefits from observations at multiple locations. In addition, NoDDAC data can be correlated with radio and ionospheric propagation changes, as well as geomagnetic activity, to investigate the connection between optical aurora and radio science. This project is unique; utilizing dual cameras with COTS equipment, emphasizing open data as a responsive community resource, and promoting citizen science make it an accessible resource benefing multiple audiences. Since early 2021, NoDDAC has detected aurora on more than 20 occasions, as well as unusual events like overhead auroras, STEVEs, and noctilucent clouds.\ 

NoDDAC is stationed at Martens Observatory (48.1{\textdegree}N), which is operated by the UND Department of Physics and Astrophysics. Live Aurora Network housings weatherproof both cameras, and their proprietary IPTimelapse software uploads images to a web server for analysis. The north-facing camera records video, allowing Zooniverse-style citizen science for small auroral features. Live Aurora Network streams both cameras on their website and app. Ultimately, when aurora is detected IPTimelapse will post a clip of the display to @NODDAC_cameras on Twitter. Automated reports will be mapped on Aurorasaurus, alongside citizen scientist observations. Image data are archived according to open source and FAIR data principles. NoDDAC will also look for crossovers with projects such as the Personal Space Weather Station to provide additional ground-based measurements of the space environment. This presentation will reflect on the data captured with NoDDAC and outline a timeline for its future, and open the floor for collaborations with other citizen science efforts.

}, author = {Vincent Ledvina and Elizabeth MacDonald and Laura Brandt and Michael McCormack and Steve Collins and Wayne Barkhouse and Timothy Young} } @proceedings {649, title = {PHaRLAP: Provision of High-frequency Ray tracing LAboratory for Propagation studies}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

PHaRLAP is a MATLAB-based toolbox created by Australia{\textquoteright}s Defence Science and Technology Group for studying and modelling HF radio wave propagation through the Earth{\textquoteright}s ionosphere. It provides a variety of ray tracing engines and necessary supporting routines. The ray tracing engines include full 3D magneto-ionic numerical ray tracing (3D NRT), 2D numerical ray tracing (2D NRT) and analytic ray tracing (ART). Propagation losses, focusing/defocusing, ionospheric absorption, ground forward scatter and backscatter losses, backscatter due to field aligned irregularities, O-X mode splitting (including power coupled into each mode) are\ all able to be modelled. This presentation describes PHaRLAP and gives examples of its use to solve real-world problems.

}, author = {Manuel Cervera} } @proceedings {641, title = {Ray Tracing in Python Utilizing the PHaRLAP Engine}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Provision of High-Frequency Raytracing Laboratory for Propagation (PHaRLAP) is an ionospheric ray tracing library developed by the Australian Department of Defence (DOD). PHaRLAP is freely available as a MATLAB toolbox downloadable from an Australian DOD website. PHaRLAP is capable of numerically ray tracing radio propagation paths using 2D and 3D algorithms through model ionospheres, most typically the International Reference Ionosphere (IRI). In an effort to make PHaRLAP available to a wider user community we are porting the PHaRLAP MATLAB toolbox to the open source Python 3 language while retaining the original core PHaRLAP computational engine. In this presentation, we describe the architecture of the new Python 3 PHaRLAP interface and demonstrate examples of 2D ray traces using the new interface.

}, author = {Alexander Calderon and William Liles and Nathaniel Frissell and Joshua Vega} } @proceedings {600, title = {SMART -- Expanding Array of Low Cost Magnetometers}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

The SMART (Surface Magnetic Assessment in Real Time) Network is a collection of 14 UCLA ground magnetometer systems across the US. Our main objective is to investigate outstanding questions in both travel-time and normal-mode magnetoseismologies. These detectors are very effective but expensive to build and maintain.\  SMART is a project to spread sensors to schools and perhaps private individuals. Broader impacts include training students in magnetic field measurements and geospace science. This provides outreach activities to schools hosting SMART systems and will provide SMART magnetometer data collected in the contiguous US to the public. 2020/2021 was time to investigate various solid state and coil systems to find detectors robust, simple, quiet and precise enough to give us reasonable measurements. Solid state and coil systems were built and compared. Finally, two systems met our requirements: RM3100 and FLC-100 coil sensors. Buried in the ground (away from temperature changes and movement) the two sensor systems compare favorably to the Falcon Search Coil system used here for the past 11 years. We will show comparative data in quiet and active times.\  We also discuss the various sensitivities of these sensors to electronic and temperature\  changes. We present a simple Raspberry Pi system that samples each of these detectors and uploads the data to google and adafuit.com clouds. We present details on construction and wiring of the system. Especially important is how to insulate and bury sensors to they see real magnet changes. Also presented will be estimated costs and availability of components. Our goal is to provide a simple and low-cost system for local measurement of the geomagnetic field.\  Additionally, the SMART team has restored many of the original UCLA sensors to operation and begun collection of data. As others build similar systems, we hope to bring many sensors into our array.

}, author = {Noel Petit and Peter Chi} } @proceedings {629, title = {TangerineSDR Architecture and Hardware Update}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

We will explain the Tangerine ecosystem and how it stacks up against other radio systems. Learn about the Clock Module (CKM), RF Module (RFM), Data Engine (DE), Magnetometer Module, VLF Receiver Module and the two newest modules, the DE Adapter and the CKM Carrier. The modular and useful approach of the TangerineSDR will allow users to build many different radio configurations at many price-points. The hardware status will be presented in light of the current supply-chain shortages.

}, author = {Scott H. Cowling} } @proceedings {625, title = {Three Time-of-Flight Measurement Projects on a Common Hardware Platform}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Three undergraduate electrical engineering project groups at Case Western Reserve University are investigating distributed ionospheric sounding through time-of-flight measurements.\  All use GPS pulse-per-second signals for precise timing of received signals.\  Two use as their "radar signals of opportunity" LF, MF, and HF beacons from the US Department of Commerce National Institute of Science and Technology installations north of Fort Collins, Colorado and near Kekaha, Hawaii (radio stations WWVB, WWV, and WWVH).\  The third project modernizes the on-off telegraphy variant known as "coherent CW" (CCW). CCW uses amateur radio QSO or beacon transmissions as the measured signals.\  It facilitates Technician-licensee participation in active HF research and in keyboard-to-keyboard digital contacts, within FCC regulations.\  Using computed matched-filter techniques along the lines of FT8, CCW has a nearly optimal information-theoretic data recovery.\  With transmission or lookup of station locations, it can provide automated time of flight measurements while making a contact.\  The three projects use a common hardware platform for receiver or transceiver interfacing, involving synchronized analog data collection and front-end data processing with the Teensy variant of the Arduino platform.\  Teensy was chosen primarily for its sampling and computing speed. WWVB{\textquoteright}s signal can be sampled directly with the Teensy front-end and some data processing can done between sample acquisitions through timer interrupt programming.\  WWV/H second ticks delay measurements use inexpensive shortwave radio audio outputs, sampled and processed by the Teensy.\  The CCW sampling and matched filtering, plus synchronized Morse keying, are similarly done by the Teensy. Data presentation, user interface, and data uploading to repositories are done by minimal general purpose computers such as Raspberry Pi boards.\  We will present the common hardware and interrupt strategies along with a brief overview of the three projects.\  Comments and suggestions will be solicited, and of course participation in the projects is invited.\  The three projects are supported by a generous grant to the Case Amateur Radio Club W8EDU from ARDC.\  CARC is providing oversight of the projects and the projects use the club station as a laboratory facility.

}, author = {David Kazdan and John Gibbons and Kristina Collins and Maxwell Bauer and Evan Bender and Ryan Marks and Michael O{\textquoteright}Brien and Olivia O{\textquoteright}Brien and Gabriel Foss and Mari Pugliese and Alejandra Ramos and Carolina Whitaker} } @proceedings {618, title = {Viability of Nowcasting Solar Flare-Driven Radio-Blackouts Using SuperDARN HF Radars}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

The first space weather impact of a solar flare is radio blackout across the dayside of the Earth. At a delay of just 8 minutes, the arrival of enhanced X-ray and EUV radiation leads to a dramatic increase in ionization density in the lower ionosphere. Operation of HF systems are often completely suppressed due to anomalous absorption, while many RF systems suffer some degradation. While the onset of blackout is very rapid (1-minute), the recovery takes tens of minutes to hours. Furthermore, severe solar flares can disrupt emergency HF communications that support humanitarian aid services, including amateur radio and satellite communication systems. Our current monitoring capability is based on modeling the ionospheric impacts based on GOES satellite observations of solar fluxes. We present a technique to characterize radio blackout following solar flares using HF radar. The future extension of this work is to develop an now-casting system to identify and monitor radio blackouts using HF radars currently deployed to support space science research. Networks of such radars operate continuously in the northern and southern hemisphere as part of the SuperDARN collaboration. Recent studies have shown that radio blackout (also known as shortwave fadeout) is easily detected and characterized using radar observations. We will combine real-time observations from the North American suite of SuperDARN radars to specify the occurrence of radio blackouts in near real-time.

}, author = {Shibaji Chakraborty and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {651, title = {WWV/H Scientific Modulation Working Group: Designing for Citizen Science}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Time standard stations WWV and WWVH have served the National Institute of Standards and Technology{\textquoteright}s time dissemination needs for the past century. Because of the stations{\textquoteright} dependability and the precision of their frequency control, their carriers have served as a measurement signal in ionospheric sensing work for over half that time. Until now, however, the possibilities for additional science-driven modulations have not been fully explored. Here, we report a characterization signal which is currently being broadcast at 8 minutes past the hour on WWV and (44) minutes past the hour on WWVH from 15 November, its design process, and initial measurements made of that signal. (www.hamsci.org/wwv). This signal serves dual purpose: to characterize the stations{\textquoteright} transmitters and to prototype waveforms that can be incorporated into the existing broadcast schedule for citizen science measurements in the future. We discuss opportunities for this signal as a citizen science tool and introduce a planned campaign of measurements April 30-May 1 2022 (www.hamsci.org/sunrisefest).\ 

}, author = {Kristina V. Collins} } @conference {586, title = {Amateur Radio Communications as a Novel Sensor of Large Scale Traveling Ionospheric Disturbances (Invited)}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Amateur (ham) radio high frequency (HF) communications are routinely observed by automated receiving systems on a quasi-global scale. As these signals are modulated by the ionosphere, it is possible to use these observations to remotely sense ionospheric dynamics and the coupled geospace environment. In this presentation, we demonstrate the use of these data to observe Large Scale Traveling Ionospheric Disturbances (LSTIDs), which are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected simultaneously over the continental United States in observations made by global HF amateur radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and discuss possible reasons why LSTIDs were observed in November but not May.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/822746}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Steven R. and Joshi, Dev Raj and Engelke, William and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {575, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=23773}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth W. and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Harvey, Lynn and Luetzelschwab, R. Carl} } @conference {582, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T ≈30-180 min, horizontal phase velocities vH≈ 100- 250 m/s, and horizontal wavelengths H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/1000724}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth and Harvey, Lynn and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @conference {581, title = {Construction and Operation of a HamSCI Grape Version 1 Personal Space Weather Station: A Citizen Scientist{\textquoteright}s Perspective}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Measurement of Doppler shifts of high frequency (HF) radio signals emitted by precision frequency transmitters is a well-established technique for the detection of traveling ionospheric disturbances and other perturbations in the bottomside ionosphere. Because Doppler measurements require minimal instrumentation, this technique naturally lends itself to crowdsourced data collection, and purpose-built instrumentation platforms are desirable in order to maximize consistency and repeatability. However, even the best system only has value if it is used, and a robust and engaged community of citizen scientists is vital to sustaining instrumentation platforms. The Ham Radio Science Citizen Investigation (HamSCI) has developed a prototype, low-cost system for making HF Doppler shift measurements of signals from standards stations such as WWV (Fort Collins, Colorado, USA) and CHU (Ottawa, Ontario, Canada). This system, known as the Personal Space Weather Station Grape Version 1, consists of a low intermediate frequency (IF) mixer board, GPS disciplined oscillator, and Raspberry Pi. In collaboration with funded project scientists and engineers, volunteer HamSCI community members developed instructions for building and operating a Grape Version 1 on the HamSCI website. In this presentation, we explain the process for constructing a Grape Version 1 and discuss the experiences of volunteers who have built and are now operating this system. We also discuss preliminary data from these stations, which show dramatic Doppler shifts during sunrise and sunset and during solar events. Concurrent data from multiple proximal stations show shared features and can be used for validation. These stations constitute the first iteration of the Personal Space Weather Station network.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/845691}, author = {Hobart, Joseph R. and Farmer, James O. and Mikitin, Gary and Waugh, David and Benedict, Robert and Cerwin, Stephen A. and Collins, Kristina V, and Kazdan, David and Gibbons, John and Romanek, Veronica I. and Frissell, Nathaniel A.} } @proceedings {504, title = {Data Collection from WWV, WWVH, and WWVB: A Histoanatomy of NIST{\textquoteright}s Radio Beacon Transmissions}, year = {2021}, month = {03/2021}, abstract = {

Beacon radio stations WWV, WWVH, and WWVB are maintained by the National Institute of Standards and Technology for frequency and time of day distribution.\  Their accuracy and power level are adequate to make the stations suitable for use as passive beacons in ionospheric sounding.\  The signals{\textquoteright} carriers are useful in measurements, and each of the modulation components has its own separate utility, as well. This poster describes several approaches to determining total path length rate of change from the stations to distant receivers through measurements of various signal parts. Tradeoffs for the several approaches in signal strength to noise ratio, ability to distinguish signals from multiple time standard stations, and other factors are discussed.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=65-9B-EB-D7-81-ED-65-2D-38-C6-5F-CB-F3-ED-B2-B0}, author = {David Kazdan and Kristina V. Collins} } @proceedings {477, title = {December 2020 Eclipse Festival Analysis}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

A crowdsourced science experiment called the December 2020 Eclipse Festival of Frequency Measurement was carried out for the total solar eclipse across South America on December 14, 2020. Over 80 stations around the world recorded WAV files of 10 MHz time standard stations. We have undertaken to process and visualize this data, and identify geophysical features within it. This poster will summarize our work to date.\ 

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=24-20-1F-16-09-FF-74-70-E0-78-1D-88-6D-21-D5-3F}, author = {Kristina Collins and David Casente and Joanna Elia and Marius Mereckis and David Meshnick} } @proceedings {459, title = {Estimation of Ionospheric Layer Height Changes From Doppler Frequency and Time of Flight Measurements on HF Skywave Signals}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The HamSCI community has been studying apparent frequency shifts in the reception of HF skywave signals from radio station WWV in Ft. Collins, CO. WWV is a standard time and frequency station with atomic clock accuracy. If the receiving station uses a GPS Disciplined Oscillator (GPSDO) for a frequency reference, the atomic clock accuracy on both ends guarantees any observed frequency shifts are attributable only to propagation effects through the ionosphere. Causes for frequency shifts in the received signal are recognized as complex and varied. A leading candidate is Doppler shift resulting from dynamic changes in refraction layer height. These, in turn, are caused by the diurnal transitions between night and day, passage of an eclipse shadow, and ionospheric disturbances originating from solar flares or X-ray events. For the case of changing refraction layer height, an analysis of Doppler frequency and Time of Flight (TOF) data can estimate the changes in skywave path length between the transmitter and receiver.\  This data can be used in conjunction with an assumed geometric model and propagation mode to infer the corresponding height profile over time. This paper postulates one possible mechanism for observed frequency swings and presents supporting experimental evidence. Comparisons between the calculated\  height profile derived from Doppler data and data from ray trace programs and ionosonde measurements are given.

}, author = {Steven Cerwin and Kristina V. Collins and Dev Joshi and Nathaniel A. Frissell} } @proceedings {572, title = {Experimental and Computational Methods to Analyze Complex Doppler Behavior of Ionospherically Induced Doppler Shifts on HF Signals (Proceedings)}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=18161}, author = {Cerwin, Stephen A. and Collins, Kristina V. and Joshi, Dev Raj and Frissell, Nathaniel A.} } @conference {583, title = {Experimental and Computational Methods to Analyze Complex Doppler Behavior of Ionospherically Induced Doppler Shifts on HF Signals}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

The HamSCI community has been studying apparent frequency shifts in the reception of HF skywave signals from radio station WWV in Ft. Collins, CO. Causes for frequency shifts in the received signal are recognized as complex and varied. Leading candidates are Doppler shifts resulting from dynamic changes in refraction layer height and the behavior of modes at incidence angles at the cusp between escape into space and refraction back to earth. Observations have shown the most radical frequency disturbances occur during the diurnal transitions between night and day, with the morning transitions exhibiting more radical behavior than evening. Other changes in solar radiation such as passage of an eclipse shadow or solar flares produce similar results. In all cases the frequency swings were found to follow the rate of change of propagation path length. Specific behaviors studied include mode splitting, where the Doppler shift diverges into multiple overtone-related tracks, modes that abruptly manifest and disappear during the transition, and asymptotic behavior where Doppler tracks exhibit a rapid frequency change followed by extinction. A morning transition spectrogram showing some of these characteristics is shown in the accompanying figure. This paper describes experiments and analytical procedures devised to better understand these phenomena. They include Time-of-Flight measurements reconciled with a geometric model of the ionosphere to infer propagation modes, use of the geometric model to calculate layer height changes from measured Doppler shifts, and comparison of specific features between spectrogram and ionosonde data sets. Data from two morning transitions and the 2017 total eclipse are given. Plausible explanations for several aspects of observed frequency swings are postulated.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/849071}, author = {Cerwin, Stephen A. and Collins, Kristina V. and Joshi, Dev Raj and Frissell, Nathaniel A.} } @article {549, title = {Ham Radio Creates a Planet-Sized Space Weather Sensor Network}, volume = {105}, year = {2021}, month = {08/2021}, pages = {55-58}, issn = {0033-4812}, url = {https://www.arrl.org/qst}, author = {Kristina V. Collins and David Kazdan and Nathaniel Frissell} } @article {513, title = {Ham Radio Forms a Planet-Sized Space Weather Sensor Network}, journal = {Eos}, volume = {102}, year = {2021}, month = {Sep-02-2021}, doi = {10.1029/2021EO154389}, url = {https://eos.org/features/ham-radio-forms-a-planet-sized-space-weather-sensor-network}, author = {Collins, Kristina and Kazdan, David and Frissell, Nathaniel} } @conference {550, title = {HamSCI Campaign Co-Design (Panel Discussion)}, booktitle = {HamSCI Workshop 2021}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, organization = {HamSCI}, address = {Virtual}, author = {Kristina V. Collins and Nathaniel A. Frissell and Philip J. Erickson and Laura Brandt and Elizabeth MacDonald and Michael Black and Gareth Perry} } @proceedings {559, title = {HamSCI: Ham Radio Science Citizen Investigation}, year = {2021}, month = {09/2021}, publisher = {International Space Weather Action Team (ISWAT)}, address = {Virtual}, author = {Frissell, Nathaniel A. and Sanchez, Diego and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Gerzoff, Robert} } @conference {544, title = {HamSCI Personal Space Weather: Architecture and Applications to Radio Astronomy}, booktitle = {Annual (Summer) Eastern Conference}, year = {2021}, month = {07/2021}, publisher = {Society of Amateur Radio Astronomers (SARA)}, organization = {Society of Amateur Radio Astronomers (SARA)}, address = {Virtual}, abstract = {

The Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project is a citizen science initiative to develop a new modular set of ground-based instrumentation for the purpose of studying the structure and dynamics of the terrestrial ionosphere, as well as the larger, coupled geospace system. PSWS system instrumentation includes radio receivers sensitive to frequencies ranging from the very low frequency (VLF) through very high frequency (VHF) bands, a Global Navigation Satellite System (GNSS) receiver to provide Total Electron Content (TEC) measurements and serve as a precision time and frequency reference, and a ground magnetometer sensitive to ionospheric and geospace currents. Although the PSWS is designed primarily for space weather and space science, its modular and open design in both hardware and software allows for a variety of use cases. The core radio instrument of the PSWS, the TangerineSDR, is a wideband, direct sampling 100~kHz to 60~MHz field programmable gate array (FPGA)-based software defined radio (SDR) receiver with direct applicability to radio astronomy. In this paper, we describe the PSWS and TangerineSDR architecture, show examples of how the TangerineSDR could be used to observe Jovian decametric emission, and discuss the applicability of the TangerineSDR to radio astronomy in general.

}, url = {https://rasdr.org/store/books/books/journals/proceedings-of-annual-conference}, author = {Nathaniel A. Frissell and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Typinski and William D. Engelke and David R. Larsen and David G. McGaw and Hyomin Kim and David M. Witten, II and Julius M. Madey and Kristina V. Collins and John C. Gibbons and David Kazdan and Aidan Montare and Dev Raj Joshi and Veronica I. Romanek and Cuong D. Nguyen and Stephen A. Cerwin and William Liles and Jonathan D. Rizzo and Ethan S. Miller and Juha Vierinen and Philip J. Erickson and Mary Lou West} } @conference {540, title = {HamSCI Personal Space Weather Station (PSWS): Architecture and Current Status}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, author = {Nathaniel A. Frissell and Dev Joshi and Veronica I. Romanek and Kristina V. Collins and Aidan Montare and David Kazdan and John Gibbons and William D. Engelke and Travis Atkison and Hyomin Kim and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Witten and Julius Madey and H. Ward Silver and William Liles and Steven Cerwin and Philip J. Erickson and Ethan S. Miller and Juha Vierinen} } @proceedings {561, title = {HamSCI Personal Space Weather Station (PSWS): Fall 2021 Update}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=1990}, author = {Frissell, Nathaniel A. and Joshi, Dev Raj and Collins, Kristina and Montare Aidan and Kazdan, David and Engelke, William D. and Atkison, Travis and Kim, Hyomin and Cowling, Scott H. and McDermott, Thomas C. and Ackermann, John and Witten, David and Madey, Jules and Silver, H. Ward and Liles, W. and Cerwin, Stephen A. and Erickson, Phillip J. and Miller, Ethan S, and Vierinen, Juha} } @proceedings {562, title = {Hardware System Update: Data Engine, RF Module, Clock Module, Magnetometer}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=2886}, author = {Cowling, Scott H.} } @conference {539, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. We present observations of TIDs made with a network of Ham Radio Science Citizen Investigation (HamSCI) Low-Cost Personal Space Weather Stations (PSWS) with nodes located in Pennsylvania, New Jersey, and Ohio. The TIDs were detected in the Doppler shifted carrier of the received signal from the 10 MHz WWV frequency and time standard station in Fort Collins, CO. Using a lagged cross correlation analysis, we demonstrate a method for determining TID wavelength, direction, and period using the collected WWV HF Doppler shifted data.

}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Clair Trop and Kristina Collins and Gareth Perry} } @conference {545, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in a WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {Annual (Summer) Eastern Conference}, year = {2021}, month = {07/2021}, publisher = {Society of Amateur Radio Astronomers (SARA)}, organization = {Society of Amateur Radio Astronomers (SARA)}, address = {Virtual}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. One way to detect TIDs is through the use of a Grape Personal Space Weather Station (PSWS). The Grape PSWS successfully detected TIDs in the Doppler shifted carrier of the received signal from the 10 MHz WWV frequency and time standard station in Fort Collins, CO. This paper will present an explanation of how the Grape PSWS was used to collect data, and how scientist can use this data to further investigate the ionosphere.

}, url = {https://rasdr.org/store/books/books/journals/proceedings-of-annual-conference}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Raj Joshi and William Liles and Claire C. Trop and Kristina V. Collins and Gareth W. Perry} } @proceedings {578, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in the WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/kVY3E3e--_I?t=3495}, author = {Romanek, Veronica I. and Frissell, Nathaniel A. and Joshi, Dev Raj and Liles, William and Trop, Claire and Collins, Kristina and Perry, Gareth W.} } @conference {580, title = {HF Doppler Observations of Traveling Ionospheric Disturbances in the WWV Signal Received with a Network of Low-Cost HamSCI Personal Space Weather Stations}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are quasi-periodic variations in ionospheric electron density that are often associated with atmospheric gravity waves. TIDs cause amplitude and frequency variations in high frequency (HF, 3-30 MHz) refracted radio waves. We present observations of TIDs made with a network of Ham Radio Science Citizen Investigation (HamSCI) Low-Cost Personal Space Weather Stations (PSWS) with nodes located in Pennsylvania, New Jersey, and Ohio. The TIDs were detected in the Doppler shifted carrier of the received signal from the WWV frequency and time standard station near Fort Collins, CO. Using a lagged cross correlation analysis, we demonstrate a method for determining TID wavelength, direction, and period using the collected WWV HF Doppler shifted data.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/888443}, author = {Romanek, Veronica I. and Frissell, Nathaniel A. and Joshi, Dev Raj and Liles, William and Trop, Clair and Collins, Kristina and Perry, Gareth W.} } @proceedings {483, title = {InFlaMo {\textendash} an European SID Monitoring Network Celebrates its First Solar Cycle}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The influence of solar X-ray radiation on terrestrial radio communication was found in the early 20ies century. But it was not understood immediately. Radio communication was a challenging topic back then, and became quickly a topic taught in science classes at school. Half a century later {\textendash} with the start of the space age - it became evident, that the study of Earth{\textquoteright}s upper atmosphere was solving this question. Solar and other cosmic radiation is responsible for the condition of the ionosphere and the cause of black-outs in long range radio communication. Today, most of the ionospheric very long frequency (VLF) radio propagation phenomena are known and presumably almost completely understood, though it stays a challenging topic listening to the ionospheric disturbances caused by our Sun. The recent development of low-cost software defined radio wave receivers (SDRs) are an ongoing process and opens many new opportunities for applications in people{\textquoteright}s daily lives and in education. Furthermore, monitoring of Earth{\textquoteright}s lower ionosphere by utilizing VLF monitors, which are based on SDR technology, it offers new indirect insights into what happens on the Sun. Therefore, one aim of this presentation is to reach out to an educator community as well as citizen scientists to make the InFlaMo (Indirect solar Flare Monitoring) project (http://www.inflamo.org) better known. For almost the entire solar cycle 24 VLF data (20 to 30 kHz) was collected and preprocessed. The scientific analysis of the VLF data is an ongoing activity. For scientific and educational use InFlaMo project data is shared with researchers, educators and citizen scientists. The other aim is to enlarge the network of ground based multichannel SDR-receivers from Europe to overseas. The European network stations have been or are presently in Germany, Finland, Russian Federation and Czech Republic. With this rather inexpensive method monitoring the state of the ionosphere and recording the appearance of solar X-ray flares can be made available for class-room usage.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=B3-60-56-B3-59-06-92-97-C6-9C-F3-8A-9B-41-D1-59}, author = {Michael Danielides and V. Skripatchev and J. Chum} } @proceedings {495, title = {K2MFF: Nearly a Century of Advancing the Radio Art at NJIT}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The New Jersey Institute of Technology Amateur Radio Club (NJITARC), K2MFF, has been an active part of the NJIT community for nearly a century.\  K2MFF has been a diligent community member, volunteering in such large-scale events as the New York City Marathon for over 30 years.\  Not only that, K2MFF, has been a fertile ground for developing young technical talent and advances in the radio art.\  Indeed, K2MFF has been a supporter and contributor to the HamSCI effort since its inception.\  In this presentation, we will offer a brief history of K2MFF, and discuss the current status and activities of the club.\  We will also offer some prognosis of the club{\textquoteright}s future directions.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=6A-73-A8-1F-B3-F9-DE-00-42-92-9A-F7-6B-59-C4-ED}, author = {Gareth W. Perry and F. Chu and Peter Teklinski} } @conference {585, title = {Observations of Mid-latitude Irregularities Using the Oblique Ionosonde Sounding Mode for the HamSCI Personal Space Weather Station}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

The spread in the echoes of high-frequency (HF, 3-30 MHz) radio waves from the F-region of the ionosphere was one of the earliest indications of plasma density irregularities in the mid-latitude F region ionosphere. Although mid-latitude spread F has been widely studied, the plasma instability mechanisms that create these irregularities are still largely unknown. This phenomenon can cause radio wave scintillation effects that degrade the performance of human-made technologies such as satellite communications and Global Navigation Satellite Systems (GNSS). Understanding these irregularities so that they can be anticipated and mitigated are important aspects of space weather research. The occurrence climatology and variability can also be helpful in validating models of these irregularities. Here, we present signatures of mid-latitude irregularities observed in oblique ionograms received near Scranton, PA transmitted by the Relocatable Over-the-Horizon Radar (ROTHR) in Chesapeake, Virginia. These observations are collected with the GNU Chirpsounder2 software, an open source software package capable of creating ionograms from frequency modulated (FM) chirp ionosondes. This ionospheric sounding mode will be implemented in the currently under-development Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS), a ground-based multi-instrument system designed to remote-sense the ionosphere using signals of opportunity. Using the data from the oblique ionograms, we generate the Range Time Intensity (RTI) plots that show ionospheric dynamics through measured path length variations as a function of time. We also compare the RTI plots with Range-Time-Parameter (RTP) plots from the SuperDARN HF radar in Blackstone, Virginia which commonly observes direct backscatter from decameter-scale irregularities within the region of ionosphere traversed by the ROTHR signal.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/875589}, author = {Joshi, Dev Raj and Frissell, Nathaniel A. and Sarwar, M. Shaaf and Sami, Simal and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Coster, Anthea J. and Erickson, Philip J. and Liles, William and Vierinen, Juha and Groves, Keith} } @conference {537, title = {Observing Large Scale Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Climatology with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications. LSTIDs create concavities in the ionospheric electron density profile that move horizontally with the LSTID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. This phenomena manifests as quasi-periodic variations in contact ranges in HF amateur radio communications recorded by automated monitoring systems such as RBN and WSPRNet. In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity as well as using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector, season, and geomagnetic activity level. Connections to neutral atmospheric sources are also explored.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {465, title = {Observing Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Validation and Climatology}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T\ \approx30-180\ min, horizontal phase velocities v_H\approx‍100-‍250 m/s, and horizontal wavelengths \lambda_H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). First in this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a case study showing consistency in LSTID signatures in RBN and WSPRNet are also present in Super Dual Auroral Radar Network (SuperDARN), Global Navigation Satellite System (GNSS), and ionosonde measurements. Then, we present a climatology of LSTID activity as well as\  using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {460, title = {Preliminary Data Analysis of PSWS Magnetometer Data}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

We report on the preliminary analysis of data obtained from newly developed magnetometers as part of HamSCI Personal Space Weather Station (PSWS) project. These systems are designed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ low-cost, commercial off-the-shelf, magneto-inductive sensor technology to record three-axis magnetic field variations with an adequate field resolution of ~10 nT at a 1 Hz sample rate. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability in unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at three locations across the US are presented and compared with the existing magnetometers nearby.\ 

}, author = {Hyomin Kim and Julius Madey and David M. Witten II and David Larsen and Scott H. Cowling and Nathaniel A. Frissell and James Weygand} } @proceedings {498, title = {PSWS Grape Hardware: Version 1.0 and Pilot Experiments}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

One year into our NSF grant, HamSCI{\textquoteright}s Low-Cost Personal Space Weather Station is undergoing rapid development. Like its namesake, the "Grape" does its best work in bunches, and several early prototypes are already deployed and collecting Doppler data. This talk will present the Grape 1.0 hardware, the data collected by pilot stations, and the lessons this platform has taught us as we move to Grape 2.0.

}, author = {Kristina V. Collins and John Gibbons and David Kazdan} } @proceedings {500, title = {PSWS Ground Magnetometer Hardware}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The path from candidate device for the magnetometer function of the PSWS to practical affordable working 24/7 data collection installations based on the low cost and readily available PNI RM3100 magneto-inductive sensor is discussed.\  Initial support board design using i2c bus connection to the host Odroid or Raspberry Pi class microprocessors with support for remote extension of the sensor to at least 100 feet with common CAT5 networking cable will be described as well as the accompanying test and logging software.\  Details of initial testing which revealed the need for temperature stabilization of the RM3100, verified remote operation to at least 500 feet, the subsequent design of an in-ground sensor housing made from common PVC water pipe and fittings and refinement of the microprocessor adapter board and remote board will be presented.

}, author = {Julius Madey and David Witten, II and Hyomin Kim and David Larsen and Scott H. Cowling and Nathaniel A. Frissell} } @proceedings {563, title = {PSWS Magnetometer Science Update}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=4555}, author = {Kim, Hyomin and Madey, Julius and Witten, David and Larsen, David R. and Cowling, Scott H. and Frissell, Nathaniel A. and Weygand, James} } @proceedings {490, title = {SMART Ground Based Magnetometer Array - an Initial Look}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Augsburg University has been involved with ground based magnetometers for the past 25 or so years. These magnetometers monitor the earth{\textquoteright}s magnetic field and its changes as the ionospheric field is perturbed by solar wind and other influences. As part of an array of detectors, we monitor the fields here in Minnesota with a flux gate magnetometer as part of the UCLA "Smart" array. This detector is sensitive to about 10 nano tesla and located in an electronically quiet hillside.\ 

In addition, in the past few years a number of solid state detectors have been integrated into easy to monitor circuits and mated with the Raspberry Pi microcomputer. Most of these cost a few dollars and if placed away from metalic influence can give reasonable measurements -- especially of large changes in local field. Specifically, we will show the output from the LIS3MDL magnetometer compared to a high cost fluxgate system. Also discussed are the GY-511(LSM303) and GY-271 (HMC5883L) Compass/Magnetometers.\ 

These data are passed to io.adafruit.com a cloud storage/plotting system that provides access to plots and data for other to monitor. Cloud services allow many users to access a wide network of data without any programming or management of the cloud. With the onset of the next solar cycle, home monitors will become useful in propagation estimates.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=D1-53-61-0E-39-F6-CA-23-13-5A-67-79-FF-84-94-E0}, author = {Noel J. Petit and Peter Chi} } @conference {542, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in simultaneously over the continental United States in observations made by global High Frequency (HF) amateur (ham) radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and that seasonal neutral atmospheric conditions may play a role in preventing AGW propagation in May but not in November.

}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Gareth W. Perry and Dev Joshi and William D. Engelke and Evan G. Thomas and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {555, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {05/2021}, publisher = {SANSA}, address = {Virtual}, url = {https://www.sansa.org.za/events-outreach/superdarn-workshop-2021/}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {574, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=22608}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {466, title = {Statistical Perspectives On the Human Factor in Spot Data from RBN and WSPR Networks}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The amateur radio reporting networks RBN and WSPRnet generate a wealth of data that can be used to great advantage in scientific research, and previous analyses of these data have shown that space weather events and ionospheric disturbances can be detected through patterns in the spot data. Although the spots recorded by the network undoubtedly reflect such changes in the natural environment, these patterns are confounded with the effects of human behaviors, such as the geographic dispersion of ham radio operators, time preferences among operators, and different levels of activity for different stations.\  Statistical models have the potential to estimate these {\textquotedblleft}human effects{\textquotedblright} and decouple them from the natural process that makes propagation possible. We will present a statistical modeling approach for these data that accounts for the non-probabilistic sampling methods that produce them.\  We will also present Spot Watcher, an app that we are developing for visualization of spots using open source tools, and comment on some of the pre-processing challenges in statistical analysis of spot data.

}, author = {David Campbell and Deborah Kunkel} } @proceedings {478, title = {A Survey of HF Doppler TID Signatures Observed Using a Grape in New Jersey}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=6A-B6-94-74-A1-46-CF-D2-AC-BA-F3-58-2E-71-17-97}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Kristina Collins and John Gibbons and David Kazdan} } @proceedings {502, title = {TangerineSDR Data Engine and Overall Architecture}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

First conceived in 2018 at the ARRL/TAPR Alubuquerque Digital Communications Conference, the modular TangerineSDR has gone through many architecture changes and upgrades. The first use case will be the Personal Space Weather Station (PSWS). The boardset consists of three custom boards: the Data Engine (DE), the Clock Module (CKM) and the RF Module (RFM). Now that we are nearing prototype hardware, here is an overview of the final architecture and the status of the prototype build.

}, author = {Scott H. Cowling and Tom McDermott and John Ackermann} } @proceedings {509, title = {TangerineSDR for the HamSCI Personal Space Weather Station}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The TangerinSDR is a modular SDR serving several use cases. The first use case will be hardware for the HamSCI Personal Space Weather Station, or PSWS. Take a look here for hardware details of the TangerineSDR from TAPR and how it will support the HamSCI PSWS!

}, author = {Scott H. Cowling} } @proceedings {469, title = {Viability of nowcasting solar flare-driven radio-blackouts using SuperDARN HF radars}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, abstract = {

The first space weather impact of a solar flare is radio blackout across the dayside of the Earth. At a delay of just 8 minutes, the arrival of enhanced X-ray and EUV radiation leads to a dramatic increase in ionization density in the lower ionosphere. Operation of HF systems are often completely suppressed due to anomalous absorption, while many RF systems suffer some degradation. While the onset of blackout is very rapid (~ minutes), the recovery takes tens of minutes to hours. Furthermore, severe solar flares can disrupt emergency HF communications that support humanitarian aid services, including amateur radio and satellite communication systems. Our current monitoring capability is based on modeling the ionospheric impacts based on GOES satellite observations of solar fluxes. We present a technique to characterize radio blackout following solar flares using HF radar. The future extension of this work is to develop an early warning system to identify \& monitor radio blackouts using HF radars currently deployed to support space science research. Networks of such radars operate continuously in the northern and southern hemisphere as part of the SuperDARN collaboration. Recent studies have shown that radio blackout (also known as shortwave fadeout) is easily detected and characterized using radar observations. We will combine real-time observations from the North American suite of SuperDARN radars to specify the occurrence of radio blackouts in near real-time. In this study, however, we present investigation and recognition techniques of shortwave fadeouts in SuperDARN HF radar.

}, author = {Shibaji Chakraborty and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {494, title = {W3USR and The Great Collegiate Shortwave Listening Contest}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/Default.aspx?s=1B-12-5C-9B-5C-AF-F5-8B-AC-62-CD-DD-D5-51-6A-9A}, author = {M. Shaaf Sarwar and Veronica I. Romanek and Thomas Baran and Jonathan Rizzo and Steve Holguin and Jonathan Rizzo and Nathaniel A. Frissell and William Liles and Kristina Collins and David Kazdan} } @proceedings {514, title = {W8EDU: Case Amateur Radio Club from 2010 to 2021}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

W8EDU, 2010-2021: In ten years, the Case Amateur Radio Club has grown from a small alumni-based group to a large student organization with extensive curricular and research involvement. This poster shows some of our successful efforts in that time, and highlights how our operating, licensing, curricular and research efforts support one another.\ 

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=B5-39-13-BC-26-3A-2E-F1-35-30-97-99-27-96-4D-CD}, author = {Kristina V. Collins and Aidan Montare and David Kazdan} } @proceedings {570, title = {WWV/H Scientific Modulation Working Group}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=15420}, author = {Collins, Kristina V.} } @conference {440, title = {Characterizing and Optimizing the behavior of a Ground-based Magnetometer for Ionospheric Space Weather Observations}, booktitle = {ARRL-TAPR Digital Communications Conference}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, organization = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Witten III, David and Kim, Hyomin and Madey, Julius and Cowling, Scotty and Frissell, Nathaniel A.} } @proceedings {433, title = {Early Results of Festival of Frequency Measurement Experiment and June 21, 2020 Asian Eclipse}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Colllins, Kristina V.} } @article {428, title = {The Great Collegiate Shortwave Listening Contest}, year = {2020}, author = {Frissell, N. A. and Liles, W. and Collins, K. and Kazdan, D} } @conference {424, title = {HamSCI Distributed Array of Small Instruments Personal Space Weather Station (DASI-PSWS): Architecture and Current Status (Invited)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {N. A. Frissell and D. Joshi and K. Collins and A. Montare and D. Kazdan and J. Gibbons and S. Mandal and W. Engelke and T. Atkison and H. Kim and A. J. Gerrard and J. S. Vega and S. H. Cowling and T. C. McDermott and J. Ackermann and D. Witten and H. W. Silver and W. Liles and S. Cerwin and P. J. Erickson and E. S. Miller} } @article {357, title = {Hands-On-SDR: TangerineSDR}, year = {2020}, month = {01/2020}, pages = {10-15}, abstract = {

The inspiration for TangerineSDR came from the HamSCI [8] group as a request for SDR hardware that could be used as a Personal Space Weather Station (PSWS). Their need resulted in the four-hour Sunday seminar at the TAPR Digital Communications Conference in Albuquerque, NM, on September 16, 2018. At TAPR, our first response was, {\textquotedblleft}Let{\textquoteright}s find a commercial SDR that we can incorporate into a PSWS kit{\textquotedblright}. Existing hardware would be our best bet for a quick solution. After some research and further consultation with the scientists at HamSCI, it became clear that there was no affordable (less than US $500) solution that met PSWS\ requirements. This article explains the TangerineSDR project and requirements.

Reprinted with permission; copyright ARRL.

}, issn = {0886-8093}, url = {http://www.arrl.org/qex/}, author = {Scotty Cowling} } @proceedings {432, title = {HF Propagation Measurement Techniques and Analyses}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Cerwin, S.} } @conference {390, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications
and associated Joule heating.

}, author = {D. Sanchez and N. A. Frissell and G. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker} } @conference {425, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, GNSS TEC, and Ionosondes}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {D. F. Sanchez and N. A. Frissell and G. W. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker and R. C. Luetzelschawb} } @conference {378, title = {Synchronized Multiple Radio Telescope Microwave SETI}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Almost all radio SETI experiments conducted to date have used antenna and receiver systems that search for semi-continuous CW beacons. Amateur radio operators are now conducting a different type of radio SETI experiment that we believe has not yet been tried. We utilize multiple geographically-spaced, synchronized radio telescopes to simultaneously scan the sky, searching for narrow bandwidth pulses and hypothetical modulated signals, containing information transmitted by extraterrestrial intelligence. We determine if pulses are simultaneously received on the same frequency, at the same time, on two or more of the radio telescopes. The signal detection system eliminates almost all terrestrial and space-based radio frequency interference. Three radio telescopes currently comprise the system: 60 foot diameter dish near Haswell, Colorado operated by Steve Plock KL7IZW, 40 foot diameter dish at the Green Bank Observatory, West Virginia, operated by Skip Crilly K7ETI, and 26 foot diameter dish in New Hampshire, remotely operated by Skip. We transit scan -7.6 degree declination and synchronously receive signals in the range of 1395 to 1455 MHz, in 16 million 3.7 Hz bandwidth channels, using four high speed computers with programmed SDR. Synchronized radio telescope observations have been conducted between late 2017 and December 2019. All raw data from observations is immediately made available upon request to interested students and researchers, to allow searches for interesting signals. Since August 2018, a total of nine anomalous simultaneous pulse events have been observed on pairs of synchronized radio telescopes, from an apparent single celestial pointing direction, at approximately 5.2 hours Right Ascension and -7.6 degrees Declination, near Rigel in Orion. A presence of modulated signals at the time of simultaneous pulses is indicated. A noise-based hypothesis has been refuted to high statistical significance. Satellite tracking experts are helping with distant space RFI hypotheses and analysis of data. Follow-up observations and system enhancement are underway. This presentation will describe the system, observations, hypothesis development and testing, and future plans. We seek ideas from listeners.

}, author = {W. J. Crilly} } @conference {372, title = {TangerineSDR Data Engine and Overall Architecture}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

A quick hardware feature review and project status of the TangerineSDR Data Engine (DE) board. Hardware components will be described, as well as a schedule time line for completion.

}, author = {S. Cowling} } @proceedings {438, title = {TangerineSDR Hardware Update}, year = {2020}, month = {09/2020}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Cowling, Scotty and Ackermann, John and McDermott, Tom} } @conference {377, title = {Update on the Low-Cost Personal Space Weather Station}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, author = {K. Collins and D. Kazdan and J. Gibbons} } @conference {379, title = {WWV Time Tick Arrival Time Study to Investigate Multiple Modes During Daily Dawn and Dusk Transitions}, booktitle = {HamSCI Workshop}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

High resolution spectral waterfall measurements of the 5 MHz WWV carrier frequency from Ft. Collins, CO to San Antonio, TX have shown the carrier to divide into the primary and additional frequency shifted copies during the night to day sunrise transition. In many cases the morning positive Doppler shifts associated with these frequencies appeared to follow a geometric progression. This timing study was conducted in an effort to learn more about multipath propagation during the dawn and dusk transitions. Timing measurements were made to arrival times of the first and delayed copies WWV 1-second timing ticks referenced to the 1 pps timing pulse available from a GPS Disciplined Oscillator. The primary and delayed arrival times were observed to cluster in a geometric progression that were consistent with ray trace programs predicting Time-Of-Flight for 1, 2, and 3 hop propagation modes. This talk presents the measurement techniques used, measured data for January 29, 2020, and correlations with a simplified geometric analysis, PHaRLAP, and Proplab Pro ray trace programs.

}, author = {S. Cerwin} } @conference {312, title = {FPGA-based HF transceiver running on an RPi with a MW loop antenna that works well indoors (Demonstration)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, author = {Cowling, Scotty} } @conference {317, title = {GPS-disciplined MEMS oscillators for amateur radio applications (Poster)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Islam - HamSCI 2019 Abstract.pdf

The frequency stability of reference oscillators (ROs) is a key performance limiter for all applications that require a timing or frequency reference, including precision sensing, inertial navigation systems, and reconfigurable radio transceivers for amateur radio. ROs based on ultra-high-Q micro-electromechanical systems (MEMS) resonators are promising replacements for conventional designs based on quartz crystals due to their compactness, amenability to monolithic integration with CMOS fabrication processes, low cost, and low power consumption. In this presentation, we will demonstrate i) a custom-designed single-chip CMOS sustaining amplifier, and ii) a highly-stable RO based on combining the amplifier with a vacuum-encapsulated breath-mode single-crystal silicon resonator (Q ≈ 105).

The free-running RO has a short-term Allan deviation $\sigma_{A}(\tau)$\ ≈ 1{\texttimes}10-8 at relatively small oscillation amplitudes (Posc ≈ -5 dBm). Further improvements in stability are obtained by increasing the oscillation amplitude such that the resonator becomes significantly nonlinear. In particular, Posc is adjusted in order to operate the resonator near one of its bifurcation points defined by electrostatic spring softening. The conversion of amplitude modulation to phase modulation (AM-to-PM) is greatly reduced near such points, thus reducing phase noise to levels that cannot be obtained using linear resonators. Thus, operation of MEMS resonators beyond the threshold of nonlinearity is promising for improving short- and medium-term RO stability. Moreover, the proposed RO can also be locked to GPS for greatly-improved long-term stability, thus enabling its use as a miniaturized, low-cost, and rugged secondary frequency standard in amateur radio applications.

}, author = {Mohammad S. Islam and George Xereas and Vamsy P. Chodavarapu and Soumyajit Mandal} } @conference {289, title = {Ionospheric Disturbances at Dawn, Dusk, and During the 2017 Eclipse}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

The author recently participated in the HamSCI propagation experiments during the August 2017 total solar eclipse and the ARRL November 2017 Frequency Measuring Test. This paper presents some interesting propagation phenomenon observed during both activities. For the eclipse experiment a well-defined propagation enhancement of both 60 kHz WWVB and 5 MHz WWV for a path between Ft. Collins, CO and San Antonio, TX was documented. Additionally, deep propagation nulls of WWVB over this path were observed to occur every morning and evening, suggesting predictable multipath interference between competing daytime and nighttime modes. During the Frequency Measuring Test, propagation-induced frequency variations of 5 MHz WWV were observed to occur at night and especially during dawn and dusk.

}, author = {Steve Cerwin} } @conference {328, title = {Ionospheric Disturbances at Dawn, Dusk, and During the 2017 Eclipse}, booktitle = {Hamvention HamSCI Forum}, year = {2019}, month = {05/2019}, publisher = {Dayton Amateur Radio Association}, organization = {Dayton Amateur Radio Association}, address = {Xenia, OH}, abstract = {

The author recently participated in the HamSCI propagation experiments during the August 2017 total solar eclipse and the ARRL November 2017 Frequency Measuring Test. This paper presents some interesting propagation phenomenon observed during both activities. For the eclipse experiment a well-defined propagation enhancement of both 60 kHz WWVB and 5 MHz WWV for a path between Ft. Collins, CO and San Antonio, TX was documented. Additionally, deep propagation nulls of WWVB over this path were observed to occur every morning and evening, suggesting predictable multipath interference between competing daytime and nighttime modes. During the Frequency Measuring Test, propagation-induced frequency variations of 5 MHz WWV were observed to occur at night and especially during dawn and dusk.

}, author = {Steve Cerwin} } @conference {361, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/581488}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Evan Markowitz and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @conference {360, title = {A Low-Cost Citizen Science HF Doppler Receiver for Measuring Ionospheric Variability}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Advancement in understanding short term and small spatial scale ionospheric variability requires global high time and spatial resolution measurements. Professional ionospheric sounding networks are extensive and capable, yet more measurements are still needed due to the strongly magnetized nature and large extent of the ionosphere. High Frequency (HF, 3-30 MHz) radio signals are refracted by the ionosphere, and therefore are modulated by processes such as traveling ionospheric disturbances (TIDs) and geomagnetic storms. By measuring the amplitude and Doppler shift of trans-ionospheric HF signals, it is possible to detect signatures of ionospheric absorption and changes in propagation path length. We present a design for a low-cost citizen science HF multi-band receiver that measures the amplitude and Doppler shift of reference signals of opportunity from the US National Institute of Standards and Technology station WWV and the Canadian Institute for National Measurement Standards station CHU. The receiver will make 1 s cadence measurements on nine HF beacon frequencies and subsequently upload the results to a central server for scientific analysis. The local user will be able to review data daily, both locally and in aggregate on a web server, and participate in discussion of the ionospheric measurements. This receiver forms one component of the low-cost version of the Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS), and is designed with the intention of distribution to hundreds to thousands of citizen science observers. Preliminary results from the prototype receiver will be presented.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/602677}, author = {Kristina Collins and David Kazdan and John Gibbons and Aidan Montare and Skylar Dannhoff and Philip J. Erickson and Nathaniel A. Frissell} } @conference {286, title = {A Modular SDR for HamSCI and Other Users}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

This presentation covers some actual hardware that can be used to fulfill the requirements of the HamSCI Personal Space Weather Station project. A new modular hardware architecture is proposed that will fulfill the requirements not only of PSWxS users, but possibly of Phase 4 Satellite Ground Station, academic research, experimenter and general SDR users as well.

}, author = {Scotty Cowling} } @conference {315, title = {PSWS Science Requirements Panel Discussion (Panel)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Moderator: Ward Silver, N0AX

  1. Phil Erickson, W1PJE, MIT Haystack Observatory, Radio, Ionospheric, \& Magnetospheric Science
  2. Nathaniel Frissell, W2NAF, NJIT, Radio, Ionospheric, \& Magnetospheric Science
  3. Hyomin Kim, KD2MCR, NJIT, Magnetospheric Physics
  4. Bill Liles, NQ6Z, VLF Science
  5. John Ackermann, N8UR, TAPR, Radio Engineering
  6. Scotty Cowling, WA2DFI, TAPR, Radio Engineering
  7. Tom McDermott, N5EG, TAPR, Radio Engineering
}, author = {John Ackermann and Scotty Cowling and Philip J. Erickson and Nathaniel A. Frissell and Hyomin Kim and William Liles and Thomas McDermott and Ward Silver} } @conference {325, title = {Sounding the Ionosphere with Signals of Opportunity in the High-Frequency (HF) Band}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

The explosion of commercial off-the-shelf (COTS) education- and consumer-grade hardware supporting software-defined radio (SDR) over the past two decades has revolutionized many aspects of radio science, bringing the cost and calibration of traditionally complex receiver hardware within the grasp of even advanced amateur experimenters. Transmission has now become the limiter of access in many cases, particularly through spectrum management and licensing considerations. Fortunately, several classes of signals endemic to the HF band lend themselves to processing for ionospheric characteristics: time and frequency standard broadcasters, surface-wave oceanographic radars, amateur radio transmissions, and ionospheric sounders.

This presentation is a tour of these signals of opportunity and techniques for collecting and processing them into ionospheric characteristics, with emphasis on distributed receivers collecting on a small number (four or fewer) of coherent channels. Receiving techniques will be discussed for near-vertical ({\textquotedblleft}quasi-vertical{\textquotedblright}) incidence skywave (NVIS or QVI), long-distance oblique soundings, and transionospheric sounding. Soundings will be demonstrated from space-based, ground-based, and maritime platforms.

Binary, Doppler, delay, cone angle of arrival, and polarization observations will be exploited, depending on the signal type and capability of the collector. Each of these techniques conveys different, but not always {\textquotedblleft}orthogonal,{\textquotedblright} information about the ionospheric skywave channel. The information content of each datum will be discussed with respect to the implications for inverting the local or regional ionosphere from the observations. More importantly than inverting the full ionosphere, some of these techniques are sensitive indicators of ionospheric irregularities, structures, and instabilities, that might otherwise be difficult to study due to limited geographic coverage with larger, more exquisite instrumentation.

}, author = {Ethan S. Miller and Gary S. Bust and Gareth W. Perry and Stephen R. Kaeppler and Juha Vierinen and Nathaniel A. Frissell and A. A. Knuth and Philip J. Erickson and Romina Nikoukar and Alexander T. Chartier and P. Santos and C. Brum and J. T. Fentzke and T. R. Hanley and Andrew J. Gerrard} } @conference {330, title = {Update on Personal Space Weather Station \& SDR Hardware}, booktitle = {Hamvention HamSCI Forum}, year = {2019}, month = {05/2019}, publisher = {Dayton Amateur Radio Association}, organization = {Dayton Amateur Radio Association}, address = {Xenia, OH}, abstract = {

The Personal Space Weather Station is a HamSCI project to create a distributed network of ground-based ionospheric and space science instrumentation. This presentation will discuss the current mission objectives and project requirements, as well as the status of current hardware development.

}, author = {Scotty Cowling} } @conference {236, title = {Initial Results of HamSCI Ham Radio 21 August 2017 Eclipse Ionospheric Experiments}, booktitle = {American Meteorological Society Annual Meeting}, year = {2018}, month = {01/2018}, publisher = {American Meteorological Society}, organization = {American Meteorological Society}, address = {Austin, TX}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. Despite more than 60 years of research, questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. We present initial results from three amateur radio experiments designed to study the 2017 total solar eclipse: the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT). These experiments are coordinated by HamSCI, the Ham Radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://ams.confex.com/ams/98Annual/webprogram/Paper337094.html}, author = {N. A. Frissell and J. R. Ackermann and D. Bern and F. Ceglia and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. Gerzoff and P. Gladstone and S. W. Gunning and J. D. Huba and J. D. Katz and E. S. Miller and M. L. Moses and S. E. Reyer and S. W. Rose and A. Shovkoplyas and H. W. Silver and P. Smith and J. S. Vega and M. L. West and R. Williams} } @article {262, title = {Ionospheric Disturbances at Dawn, Dusk, and During the 2017 Eclipse}, journal = {QEX}, year = {2018}, month = {09/2018}, pages = {8-14}, chapter = {8}, abstract = {

The author recently participated in the HamSCI propagation experiments during the August 2017 total solar eclipse, and the ARRL November 2017 Frequency Measuring Test (FMT). This article presents some interesting propagation phenomena observed during both activities. For the eclipse experiment, well-defined propagation enhancements of both 60 kHz WWVB and 5 MHz WWV for a path between Ft. Collins, CO and San Antonio, TX were documented. Additionally, deep propagation nulls of WWVB over this path were observed to occur every morning and evening, suggesting predictable multipath interference between competing daytime and nighttime modes. During the Frequency Measuring Test, propagation-induced frequency variations of 5 MHz WWV were observed at night and especially during dawn and dusk. One observed dawn frequency perturbation was particularly interesting because it occurred at a fundamental frequency shift plus two harmonically related overtones, indicating a nonlinear ionospheric response to rapidly increasing solar radiation.

}, issn = {0886-8093}, author = {Steve Cerwin} } @conference {172, title = {Analysis of the August 2017 Eclipse{\textquoteright}s Effect on Radio Wave Propagation Employing a Raytrace Algorithm}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, abstract = {

The upcoming total solar eclipse over the continental United States on August 21 offers an unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the west-to-east motion of the eclipse terminator, the duration of the event, the solar zenith angle, and the continued visibility of the corona. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses, as measured by changes in radio frequency (RF) propagation. High Frequency (HF) propagation varies greatly depending on ionospheric conditions. Hence, our analysis will include data collected during the eclipse by several HF systems shown in Figure 1 including SuperDARN, temporary radio transceiver sites, and amateur radio networks such as the Reverse Beacon Network (RBN) and Weak Signal Propagation Reporter Network (WSPRNet). The data analysis will be guided by raytrace models of HF propagation through an eclipsed ionosphere employing the HF propagation toolbox, PHaRLAP (created by Dr. Manuel Cervera).

}, author = {M. L. Moses and S. Burujupali and K. Brosie and S. Dixit and G. D. Earle and L. Kordella and N. A. Frissell and C. Chitale} } @article {231, title = {Faraday Rotation of Automatic Dependent Surveillance-Broadcast (ADS-B) Signals as a Method of Ionospheric Characterization}, journal = {Radio Sci.}, volume = {52}, year = {2017}, month = {2017}, pages = {1293 - 1300}, abstract = {

Radio waves propagating through plasma in the Earth{\textquoteright}s ambient magnetic field experience Faraday rotation; the plane of the electric field of a linearly polarized wave changes as a function of the distance travelled through a plasma. Linearly polarized radio waves at 1090 MHz frequency are emitted by Automatic Dependent Surveillance Broadcast (ADS-B) devices that are installed on most commercial aircraft. These radio waves can be detected by satellites in low Earth orbits, and the change of the polarization angle caused by propagation through the terrestrial ionosphere can be measured. In this manuscript we discuss how these measurements can be used to characterize the ionospheric conditions. In the present study, we compute the amount of Faraday rotation from a prescribed total electron content value and two of the profile parameters of the NeQuick ionospheric model.

}, keywords = {2443 Midlatitude ionosphere, 2447 Modeling and forecasting, 2467 Plasma temperature and density, 2494 Instruments and techniques, Automatic Dependent Surveillance-Broadcst (ADS-B), electron density, Faraday rotation, ionosphere, total electron content (TEC)}, isbn = {1944-799X}, doi = {10.1002/2017RS006319}, url = {http://dx.doi.org/10.1002/2017RS006319}, author = {Cushley, A. C. and Kabin, K. and No{\"e}l, J.-M.} } @conference {176, title = {Fitting Ionospheric Models Using Real-Time HF Amateur Radio Observations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {J. D. Katz and N. A. Frissell and J. S. Vega and A. J. Gerrard and R. B. Gerzoff and P. J. Erickson and E. S. Miller and M. L. Moses and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas} } @conference {163, title = {Ionospheric Impacts of the 2017 Total Solar Eclipse}, booktitle = {Dayton Hamvention}, year = {2017}, address = {Xenia, OH}, author = {Magalina Moses and Gregory Earle and Sushma Burujupalli and Nathaniel A. Frissell and Lee Kordella and Snehal Dixit and Charudatta Chitale and Xiayou Han} } @conference {173, title = {Ionospheric Simulations of the 2017 Solar Eclipse QSO Party}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and M. L. Moses and G. D. Earle and S. W. Gunning and A. J. Gerrard and E. S. Miller and M. L. West and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas and H. W. Silver} } @conference {158, title = {On the use of solar eclipses to study the ionosphere}, booktitle = {15th International Ionospheric Effects Symposium IES2017}, year = {2017}, month = {05/2017}, address = {Alexandria, VA}, abstract = {

Exploring the effects of solar eclipses on radio wave propagation has been an active area of research since the first experiments conducted in 1912. In the first few decades of ionospheric physics, researchers started to explore the natural laboratory of the upper atmosphere. Solar eclipses offered a rare opportunity to undertake an active experiment. The results stimulated much scientific discussion.
Early users of radio noticed that propagation was different during night and day. A solar eclipse provided the opportunity to study this day/night effect with much sharper boundaries than at sunrise and sunset, when gradual changes occur along with temperature changes in the atmosphere and variations in the sun angle.
Plots of amplitude time series were hypothesized to indicate the recombination rates and re- ionization rates of the ionosphere during and after the eclipse, though not all time-amplitude plots showed the same curve shapes. A few studies used multiple receivers paired with one transmitter for one eclipse, with a 5:1 ratio as the upper bound. In these cases, the signal amplitude plots generated for data received from the five receive sites for one transmitter varied greatly in shape.

}, author = {W. Liles and C. Mitchell and M. Cohen and G. Earle and N. Frissell and K. Kirby-Patel and L. Lukes and E. Miller and M. Moses and J. Nelson and J. Rockway} } @conference {144, title = {Characterizing the Ionosphere Using a Commercial Off the Shelf Software Defined Radio System}, booktitle = {Fall 2016 American Geophysical Union}, year = {2016}, month = {12/2016}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francsico}, abstract = {

On August 21, 2017, there will be a total solar eclipse over the continental United States (US). Solar eclipses offer a way to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the east-west motion of the eclipse terminator, the speed of the transition, and the continued visibility of the corona throughout the eclipse interval. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses including variations in the density and altitude of the F2 peak. In order to study these changes, we will establish four temporary field stations along the path of totality to track the maximum usable frequency (MUF) across the US over the course of the eclipse. Each field station shall consist of a commercial off the shelf (COTS) software defined radio (SDR) transceiver, a laptop computer running automatic link establishment (ALE) software, a Global Positioning System (GPS) receiver for timing, and a COTS antenna. Custom ALE software will automate the sites{\textquoteright} operation during the experiment to determine the MUF. As a validation test prior to the eclipse, we established three sites along the east coast to confirm that the SDRs are capable of inferring ionospheric conditions. The preliminary results characterize the effects of the sunrise/sunset terminator on our system{\textquoteright}s measurements as well as the change in foF2 during different seasons and under different geomagnetic conditions.

}, url = {http://hamsci.org/sites/default/files/publications/2016_AGU_Moses.pdf}, author = {Magdalina L. Moses and S. Dixit and Gregory D. Earle and Nathaniel A. Frissell and Lee Kordella and Xiaoyu Han and Charudatta Chitale} } @conference {143, title = {HamSCI: The Ham Radio Science Citizen Investigation}, booktitle = {Fall 2016 American Geophysical Union}, year = {2016}, month = {12/2016}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco}, abstract = {

Amateur (or {\textquotedblleft}ham{\textquotedblright}) radio operators are individuals with a non-pecuniary interest in radio technology, engineering, communications, science, and public service. They are licensed by their national governments to transmit on\ amateur radio frequencies. In many jurisdictions, there is no age requirement for a ham radio license, and operators from diverse backgrounds participate. There are more than 740,000 hams in the US, and over 3 million (estimated)\ worldwide. Many amateur communications are conducted using transionospheric links and thus affected by space weather and ionospheric processes. Recent technological advances have enabled the development of\ automated ham radio observation networks (e.g. the Reverse Beacon Network,\ www.reversebeacon.net) and specialized operating modes for the study of weak-signal propagation. The data from these networks have been\ shown to be useful for the study of ionospheric processes. In order to connect professional researchers with the volunteer-based ham radio community, HamSCI (Ham Radio Science Citizen Investigation,\ www.hamsci.org) has\ been established. HamSCI is a platform for publicizing and promoting projects that are consistent with the following objectives: (1) Advance scientific research and understanding through amateur radio activities. (2) Encourage\ the development of new technologies to support this research. (3) Provide educational opportunities for the amateur community and the general public. HamSCI researchers are working with the American Radio Relay League\ (ARRL,\ www.arrl.org) to publicize these objectives and recruit interested hams. The ARRL is the US national organization for amateur radio with a membership of over 170,000 and a monthly magazine, QST. HamSCI is\ currently preparing to support ionospheric research connected to the 21 Aug 2017 Total Solar Eclipse by expanding coverage of the Reverse Beacon Network and organizing a large-scale ham radio operating event ({\textquotedblleft}QSO\ Party{\textquotedblright}) to generate data during the eclipse.

}, url = {http://hamsci.org/sites/default/files/publications/2016_AGU_Frissell_HamSCI.pdf}, author = {Nathaniel A. Frissell and Magdalina L. Moses and Gregory Earle and Robert W. McGwier and Ethan S. Miller and Steven R. Kaeppler and H. Ward Silver and Felipe Ceglia and David Pascoe and Nicholas Sinanis and Peter Smith and Richard Williams and Alex Shovkoplyas and Andrew J. Gerrard} } @article {45, title = {Ionospheric Sounding Using Real-Time Amateur Radio Reporting Networks}, journal = {Space Weather}, volume = {12}, year = {2014}, pages = {651{\textendash}656}, abstract = {

Amateur radio reporting networks, such as the Reverse Beacon Network (RBN), PSKReporter, and the Weak Signal Propagation Network, are powerful tools for remote sensing the ionosphere. These voluntarily constructed and operated networks provide real-time and archival data that could be used for space weather operations, forecasting, and research. The potential exists for the study of both global and localized effects. The capability of one such network to detect space weather disturbances is demonstrated by examining the impacts on RBN-observed HF propagation paths of an X2.9 class solar flare detected by the GOES 15 satellite. Prior to the solar flare, the RBN observed strong HF propagation conditions between multiple continents, primarily Europe, North America, and South America. Immediately following the GOES 15 detection of the solar flare, the number of reported global RBN propagation paths dropped to less than 35\% that of prior observations. After the flare, the RBN showed the gradual recovery of HF propagation conditions.

}, keywords = {Instruments and techniques, ionosphere, Ionospheric effects on radio waves, Solar effects}, issn = {1542-7390}, doi = {10.1002/2014SW001132}, url = {http://hamsci.org/sites/default/files/publications/2014_SpaceWeather_Frissell_RBN.pdf}, author = {Frissell, N. A. and Miller, E. S. and Kaeppler, S. R. and Ceglia, F. and Pascoe, D. and Sinanis, N. and Smith, P. and Williams, R. and Shovkoplyas, A.} }