@article {1007, title = {Detecting changes in along-path HF propagation during the April 2024 total solar eclipse with radio amateurs and low-cost instrumentation}, journal = {Frontiers in Astronomy and Space Sciences}, year = {2026}, month = {Feb/2026}, abstract = {

The total solar eclipse of April 8, 2024 presented a uniquely favorable circumstance for radio science. The Moon{\textquoteright}s shadow passed near Canadian time standard station CHU, which transmits in the high frequency (HF,\ i.e., 3{\textendash}30 MHz) band. It was therefore possible to observe signal changes due to shifting ionospheric conditions along the path of the eclipse by using CHU as a signal of opportunity. In under 3 months, our undergraduate team developed and deployed low-cost instrumentation to record CHU for timing and amplitude analysis. 18 units were distributed across 6 locations roughly aligned with the eclipse path. Each unit contained a radio recorder which retained time traceability to UTC via GPS time synchronization, allowing capture of the CHU signal with no unbounded error beyond the 50 {\textmu}s sampling interval. Seven units captured changes in the received signal during the eclipse, most notably a tenfold increase in the signal strength at 7.85 MHz for a unit in Little Rock, AR. Its timing suggests a one-hop propagation path reflecting in the ionosphere over Cleveland, OH. The stations were deployed to and maintained by volunteers contacted through the amateur radio and citizen science community. This campaign demonstrates the accessibility and effectiveness of research using low-cost instrumentation and the power of citizen science.

}, doi = {10.3389/fspas.2025.1720301}, url = {https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2025.1720301/full}, author = {Maris Usis and Adam Goodman and Laura Schwartz and David Kazdan and Kristina Collins and John Gibbons and Shashank Sastry and Lucy Ayres and Christopher Brault and Seth Byas and Michael Dimple and Michelle Dowell and Rowan Eggert and Aras Erdag and James Ervin and Dave Goodwin and Scarlett Nelson and Stephen Nichols and Olivia Tulgetske and Christian Zorman} } @proceedings {1010, title = {HamSCI Link Budget: Observations and Modeling the Signal Strength of HF Radio Links from WWV to W2NAF}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {

This work explores the ionospheric High Frequency (HF) absorptions, specifically at 5 and 10 MHz. We investigate the HF absorption levels for the radio links from the two National Institute of Standards and Technology (NIST) dedicated Radio transmitting Stations, WWV Colorado and WWV Hawaii, to the Personal Space Weather Station (PSWS) receiver W2NAF. W2NAF, located near Scranton, Pennsylvania, is equipped with the GPS-disciplined Great Radio Amateur Propagation Experiment (GRAPE) receiver. Our work utilizes the International Reference Ionosphere (IRI-2020) model and PHaRLAP ray tracer to calculate the absorptions of the HF rays from the two WWV transmitters to W2NAF connected by 1, 2, or 3 hop links. For the modeled rays, we also calculate the percentage of successful rays connecting WWV and W2NAF. Our results show that the modeled absorptions are consistent with the signal strength observations for some of the quiet days, albeit with divergences at others. We will present these results on the data-model comparison of the Ham Radio Science Citizen Investigation (HamSCI) link budget.

}, author = {Gamal Zayed and Kuldeep Pandey and Nathaniel Frissell} } @proceedings {1027, title = {Understanding HamSCI Magnetometers Measurements and Observations: A Preliminary Report and Demonstration }, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {Ground-based magnetometers are unique instruments that allow for remote sensing of the dynamics and structure of the geospace magnetospheric environment directly from the Earth{\textquoteright}s surface. Traditionally, science-grade magnetometers for this purpose have been prohibitively expensive for individuals to operate; therefore, geomagnetic observations are normally restricted to select sites operated by research institutions and government agencies. Recent technological developments by industry and citizen science organizations have brought down the cost of magnetometer ownership and operation to a level affordable by individuals. Such a magnetometer is part of the HamSCI Personal Space Weather Station (PSWS) suite, which includes not only a ground magnetometer for magnetospheric studies, but also radio receivers for ionospheric studies. The HamSCI PSWS project is led by the University of Scranton, but research here has primarily focused on supporting the radio instrumentation of the project. In this presentation/demonstration we have established a laboratory testbed in the University of Scranton Loyola Science center. This testbed is currently being used to develop in-house expertise in the HamSCI magnetometer system to allow faculty, staff, and students at Scranton to better understand instrument operation, capabilities, limitations for the purpose of improved data analysis and support of the Citizen Science Community that will be operating these systems. In this presentation/demonstration, we will showcase how we are using it and our simulation of the Gannon Storm. }, author = {Rachel Frissell and Christine Zakzewski and Majid Mokhtari and Dave Witten and Nathaniel Frissell} } @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 {963, title = {Bridging Indoor RFID Localization and Long-Range Sensing: Exploring Energy-Efficient Backscatter Positioning}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The evolution of backscattering communications has significantly advanced RFID-based localization, particularly in scenarios where cost-effectiveness and low power consumption in harsh environments are critical. Originally introduced during World War II with the concept of corner reflectors, backscatter-based localization has since progressed into ubiquitous indoor tracking and Internet of Things (IoT) applications. However, interference, energy harvesting limitations, and communication range constraints limit its full potential. Recent advancements in RFID-based localization have focused on techniques that optimize power allocation, extend range, and mitigate interference. One approach involves integrating sensing and communication (ISAC) systems with RFID, where Zero-Forcing and Convex Optimization minimize interference while enhancing power allocation. However, as tags move closer to user antennas, interference challenges remain. Another key development in backscattering communications has demonstrated long-range RFID localization by decoupling the carrier frequency from the receiver, achieving distances up to 3.4 km at 868 MHz with only 70 μW power consumption. However, this technique introduced unintended interference with nearby communication bands. More recent methods have addressed this issue by employing frequency shift keying (FSK) modulation, significantly extending reader-tag distances. Building upon these insights, we propose an auxiliary approach: integrating energy-harvesting receiving antennas within RFID localization networks, transforming them into self-powered sensor nodes. This approach opens opportunities for radio applications, where distributed low-power RFID beacons could support experimental localization networks. With backscatter localization techniques progressing in extended range, interference mitigation, and energy efficiency, this study explores their potential for passive RF sensing and citizen science applications. By bridging RFID localization and radio science, we investigate their feasibility in long-range sensing scenarios.

}, author = {Gamal Zayed and Ahmed Saeed and Yehea Ismail} } @article {1055, title = {conjugate_map: A Python package for calculating geomagnetic conjugate points}, journal = {SoftwareX}, volume = {32}, year = {2025}, month = {01/2025}, pages = {102354}, abstract = {

The Earth{\textquoteright}s magnetic field is dominated by the dipole moment, which magnetically connects the northern and southern hemispheres. Because ionospheric and magnetospheric plasmas preferentially move along magnetic field lines, local processes that affect the ionosphere or magnetosphere in one hemisphere can cause changes in the opposite hemisphere. The polar regions are uniquely valuable in geospace science, in part because much of the solar wind{\textquoteright}s energy enters the system in polar regions and their magnetospheric, ionospheric, and atmospheric connections are markedly different from the lower latitudes. Geomagnetic conjugates are points in the northern and southern hemispheres linked by Earth{\textquoteright}s magnetic field, including both points connected by closed magnetic field lines and points in open-field line regions that are in similar magnetic domains. Conjugate locations are both affected asymmetrically by external factors and have also been shown to alter each other{\textquoteright}s environment on the order of minutes, which makes interhemispheric comparisons crucial to understanding the full dynamics of the geospace system. Here, we present\ conjugate_map, a Python library for flexible geomagnetic coordinate conversions that was designed to facilitate interhemispheric comparisons of geospace events and deployment of polar geospace instruments. As the fifth International Polar Year approaches in 2032{\textendash}33, this work will help researchers to incorporate interhemispheric geospace investigations into the instrument planning process.

}, issn = {23527110}, doi = {10.1016/j.softx.2025.102354}, url = {https://www.sciencedirect.com/science/article/pii/S2352711025003206$\#$d1e1057}, author = {Collins, Kristina and Hartinger, Michael and Zimmerman, Kelsey and Salzano, Michelle and Burrell, Angeline} } @proceedings {964, title = {Enhancing Lidar-GPS Fusion for Localization: Integrating Ionospheric Modeling with NeQuick G and V2V Implementation}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Lidar (Light Detection and Ranging) provides high-resolution mapping and odometry for localization but faces limitations when used alone. Conversely, GPS positioning is impaired by ionospheric irregularities{\textemdash}such as Total Electron Content (TEC) variations, scintillation, and gravity waves{\textemdash}which distort satellite signals and reduce accuracy. This work explores a multi-modal fusion approach that integrates Lidar and GPS to optimize localization by compensating for ionospheric-induced errors. In the first phase, we focus on enhancing the GPS component of the Lidar-GPS fusion using the Galileo-based NeQuick G model, a mathematical framework for simulating ionospheric variations. Utilizing NASA{\textquoteright}s Archive of Space Geodesy Data, we analyze the spatio-temporal distribution of Vertical TEC (VTEC). By applying Particle Swarm Optimization (PSO), we identify global VTEC maxima at different altitudes, shedding light on worst-case ionospheric disturbances. For example, our analysis predicts that on January 1, 2027, at 12:00 AM UTC, the highest VTEC values occur at coordinates (-9.8, -88) near Peru, a critical region where GPS accuracy may degrade. This phase aids in forecasting GPS performance fluctuations in high-disturbance zones and informs the optimization of Lidar-GPS fusion for precision applications, including autonomous vehicles and V2V communication. The second phase is an aspirational extension aimed at implementing a Vehicle-to-Vehicle (V2V) communication model using Lidar sensors. This planned work will address challenges such as third-vehicle occlusion and background visible light noise. By integrating Lidar landmark matching, SLAM, and 3D point cloud processing, we intend to enhance localization reliability in dynamic multi-vehicle environments. Ultimately, this study bridges atmospheric science and vehicular localization, demonstrating the synergy between Lidar-based SLAM, ionospheric modeling, and the potential for robust Lidar-driven V2V networking to improve autonomous navigation and road safety.

}, author = {Gamal Zayed and Ahmed Saeed and Yehea Ismail} } @proceedings {941, title = {Generating and Receiving GPS-Timed Acoustic and Radiofrequency Costas Array Sounding Signals}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Understanding the static and dynamic properties of the ionosphere is of great fundamental and technological importance. This work presents a low-cost, GPS-disciplined transmitter/receiver system that uses Costas arrays similar to those in FT8 to achieve simultaneous time-of-flight and Doppler shift measurements. The sharp correlation peaks in both frequency and time domains of the Costas arrays may allow for the study of difficult-to-measure properties of the HF propagation, such as the number of hops, ionospheric propagation type, etc. The narrow bandwidth and optimal autocorrelation properties also make the Costas array a good signal for the moderate noise of the HF bands and allows for QRP (low-power, under 5W) operation. Our hardware design consists of a microcontroller coupled with an AD9850 direct digital synthesis chip and an external 50 MHz crystal oscillator, as well as an Adafruit GPS module with a 1PPS signal. Our device is designed to interface with standard amateur radio transceivers for both transmission and reception. Its open-source architecture and reliance on readily available off-the-shelf parts make it easily reproducible, and suitable for rapid deployment. Some hams and institutions have already expressed interest in deploying units for coordinated data collection. By offering inexpensive, scalable, and accurate ionospheric sounding capabilities, this project aims to support ongoing research of the ionosphere and HF propagation.

}, author = {Solomon El-Ghannam and Andres Dickson Alarcon and Yaodan Zhang} } @proceedings {935, title = {High-Frequency Signal Strength Simulation at GRAPE Personal Space Weather Stations Using PHaRLAP Ray Tracing}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

High-frequency (HF) radio wave propagation serves as both a vital communication tool and a probe for ionospheric behavior. This work models and analyzes the reception of HF signals from the standard transmitting station WWV (Fort Collins, Colorado) to two well-calibrated Personal Space Weather Stations (PSWS): W2NAF (Scranton, Pennsylvania) and K6KPH (Point Reyes, California). These stations are equipped with Great Radio Amateur Propagation Experiment (GRAPE) receivers{\textemdash}GPS-disciplined systems designed to measure standard time signals with high precision. To simulate HF wave propagation, we use the Provision of High-Frequency Raytracing Laboratory for Propagation Studies (PHaRLAP), a MATLAB toolbox for ionospheric ray tracing. Utilizing the data-based International Reference Ionosphere (IRI) 2020 model, which supplies the ionospheric background conditions, we analyze HF propagation at 5, 10, and 15 MHz by launching a fan of rays at varying elevation angles to determine which rays successfully reach the receivers. In addition, we are extending our simulations using the Python-based SAMI3 ionospheric model. We also compute ionospheric HF absorption and compare the modeled values with the observed signal strengths recorded by the PSWS throughout the day, aiming for the predicted absorption to be within one order of magnitude of the observations. This work enhances our understanding of how ionospheric absorption affects HF signal strength across different times of day and seasons, thereby contributing to space science, space weather research, and amateur radio science.

}, author = {Gamal Zayed and Nathaniel Frissell and Kuldeep Pandey} } @proceedings {957, title = {How Do We Put a HamSCI Personal Space Weather Station in Antarctica?}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present initial ideas on how to place a HamSCI Personal Space Weather Station at United States Antarctic Research Stations.

}, author = {Rebecca Potter and Nina Tormann and Christine Zakzewski and Majid Mokhtari and Nathaniel Frissell and Ken Martin and Jermey McLynch and Hyomin Kim and Gareth Perry and David McGaw and James LaBelle and Tedi Godfrey and Michael Hartje and Gwyn Griffiths and Rob Robinett and Paul Elliott} } @proceedings {976, title = {University of Scranton W3USR Teaching Amateur Radio at the Lackawanna Blind Association}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Access to amateur radio can be life-changing for individuals who are blind or visually impaired. Radio communication provides an accessible, independent, and engaging way to connect with others; it helps foster both technical skills and social interactions. The University of Scranton W3USR, working in collaboration with local amateur radio operators and the Lackawanna Blind Association (LBA), has launched a program to teach amateur radio to people who are blind and visually impaired using the Handiham curriculum. This initiative enables blind and visually impaired individuals to engage with and become licensed amateur radio operators through an accessible learning experience that they look forward to each week. This project has support from all different angles and has shown some promising results.

}, author = {Thomas Pisano and Owen Ruzanski and Alexandros Papadopoulos and Lucero Alvarez and Ken Martin and William Gallagher and Christine Zakzewski and Nathaniel Frissell} } @proceedings {882, title = {High Frequency Raytracing for Studying the Ionosphere and Radio Propagation (Invited Tutorial)}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

High Frequency (HF) raytracing is a tool to study the propagation of HF radio waves through the ionosphere. This presentation will cover the basics of raytracing, including typical inputs and outputs. We will review the different physics that may be included in the raytracer and how changes in the ionosphere may affect the radio wave propagation. A brief description of how to use a raytracer for common applications will be provided. The applicable frequency ranges and limitations of this technique will be also discussed.

}, author = {Katherine Zawdie} } @proceedings {881, title = {Optimizing Location Estimation with Novel Numerical Solution using Real-Time Transmitting Beacons WSPRlive, Weak Signal Propagation Reporter Protocol, and Friis Propagation Model}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The proliferation of real datasets has become indispensable for implementing various processes in real-time scenarios. Our previous project successfully contributed to expanding data grids aimed at predicting the vertical total electron content (vTEC) for the ionosphere. Leveraging Ham Radio Networks in conjunction with data broadcasted from the International Space Station (ISS), and integrating them into the Galileo-based NeQuickG mathematical model, we developed a web-based application tailored to this purpose. In this study, the focus is on generating new data grids for location estimation within a Radio Frequency (RF) environment, relying solely on transmitter identities and measured received powers. The localization process is divided into two stages. Initially, ideal received powers are computed using the Friis propagation model, resulting in a dataset encompassing over 25,000 locations per received power. To ensure reliability, a hardware implementation of Weak Signal Propagation Reports (WSPR)-based beacons, operational 24/7, is utilized globally. This implementation, facilitated by the IntlWSPR project covering 40 spots, features beacons transmitting at 23 dBm, with maximum gains varying according to antenna types: 7 dBi for Skyloop 80-10, 5 dBi for DX Commander ABV, and 2 dBi for Q-Tek Penetrator antennas. With the ideal dataset established as a reference, location estimation becomes feasible by identifying the best beacon identities per received power for the query receiver. However, numerical solutions for the localization system involve relatively lengthy processing times and exhibit mean square localization errors, motivating the second phase of this work. A novel numerical solution enhancement technique, coupled with a designed radius of convergence, significantly accelerates the convergence of the localization system{\textquoteright}s equations with improved accuracy. Future efforts aim to integrate this enhanced approach into the real-time application, with a focus on estimating the WSPR channel propagation model using additional real data provided by the WSPRnet spot database. Although the WSPRnet spot database offers non-contiguous timed datasets, it serves as a cornerstone for training regression Machine Learning models, facilitating further refinement of the localization process.

}, author = {Gamal Zayed} } @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 {690, title = {Evaluation of Global Ionospheric TEC Using Simultaneous Observations from Amateur Radio Networks, International Space Station, and NeQuickG Model for Space Weather Prediction}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Ionospheric electron density plays a significant role in long-distance communications and sky-wave propagation. Prediction of the accurate state of the ionosphere is necessary to understand the accurate signal perturbations thereby estimating the critical parameters for better signal transmission. The space weather impacts on such trans-ionospheric technological systems are evident. In this work, a web application is developed to represent the global day-to-day electron density variations from the NeQuickG model. Also, the ground-based HAM radio broadcast network hop data with different wavelengths (eg. 10 m and 20 m) and simultaneous top-side electron density with space-based International Space Station (ISS) probe data from floating point measurement units are examined. The electron density variations for the year 2017 are clearly represented. Optimization techniques are necessary to frame a denser spatial grid-based ionospheric electron density map from all the observations. It is essential to estimate the optimal weight function that can distribute the observation influence over empty grid bins with minimum error variance through a probabilistic approach. User-understandable metrics development exclusively for Amateur radio operators and civil aviation sectors is focused. In the near future, the developed web-based application could serve as a better visualization platform for space weather forecasting.

This project, Fellowship of the Ionosphere,\ is a Global Finalist in the 2022 NASA Space Apps Challenge.\ NASA Space Apps 2022 had 31,400+ registered participants from 162 counties and territories, with\ over 3000 submissions from 5327 teams. Global Finalists are ranked as one of the top 35 projects from all submissions.

}, author = {Gamal Zayed and Marcin Lesniowski and Pasumarthi Babu Sree Harsha and Matthew Downs and Daniel Metcalfe and Sila Kardelen Karabulut} } @proceedings {749, title = {Lunar Dust Particle Simulation in the (12-6) Lennard-Jones Potential Approximation}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

We model lunar dust particles as interacting ellipsoidal dipoles by means of Lennard-Jones potentials (L-J). Lunar surface dust particles are continuously bombarded by plasma charge particles coming from the solar wind. It has been recognized that solar wind bombardment leads to strong intergrain interactions between dust particulates leading to collective effects such as attraction of charged dust particles. Formation of electrostatically ordered dust structures is believed to be due to strong attractive van der Waals-like potentials at distances in the order of interparticle separation. Dust-dust electrostatic interactions and collisions may lead to particle coalescence or dust-lumps kept together due to Coulomb forces. On the other hand, dust ionization occurs after solar wind electrons collide with grains in the plasma sheath formed on the lunar surface. Particle coalescence and to an extent condensation is feasible when an attractive potential is present. Ellipsoidal dipole condensation is possible in the presence of a Lennard-Jones (L-J) potential.

}, author = {Rachel Marie Frissell and Joseph Klobusicky and Argyrios Varonides and Amir Zamanian} } @proceedings {508, title = {Characterization of Sporadic E Propagation in WSPRNet Spot Records}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

WSPRNet is a centralized database that collects spot records from amateur radio stations operating weak digital modes. Each of the spot records provides SNR, transmitting power, and geographic information, which can be used to estimate transmission paths. While WSPRNet has primarily used to study propagation paths for HF bands, putative sporadic E propagations at VHF bands have been reported. This on-going exploratory analysis aims to characterize possible Sporadic E Propagations captured in WSPRNet records and possible correlations with solar and other weather conditions. Preliminary results confirms a lack of correlation between sporadic E propagation and F10.7 indices. The geographic distribution pattern of putative sporadic E propagation and its relationship with other space weather indices will be discussed.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=56-9E-0F-03-A5-9D-C6-20-FA-F9-00-80-42-84-4B-EA}, author = {Jeannette Zhou} } @proceedings {493, title = {Introduction of Activities at Berkeley ARC W6BB}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=19-77-7A-A0-7D-FF-C1-D6-16-E8-BE-1F-D6-F8-9E-8F}, author = {Michael Zuerch} } @proceedings {464, title = {Traveling ionospheric disturbances tracked through Doppler-shifted AM radio transmissions}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

A comprehensive understanding of the ionosphere is critical for many technologies, particularly those that rely on the propagation of radio waves. This study shows that traveling ionospheric disturbances (TIDs), dawn and dusk signal divergence (terminators), and spread F\ can be tracked and analyzed using clear channel AM radio transmissions and a set of geographically distributed receivers. Early attempts by our research group to track TIDs by AM radio signals reflected from the F region of the ionosphere generated results in conflict with those derived from GPS/TEC mapping methods [Chilcote et al., 2015]. This study seeks to resolve those conflicts with a more sophisticated array of receivers spread throughout the northeastern United States. Specifically, the receivers form a ring around an 810 kHz AM radio station in Schenectady, New York. A minimum of four receivers have been operational from 3/19/20 to the present and Doppler-shifted signals, attributed to TID events, have been consistently visible across several radio channels with frequencies between 800 to 1600kHz. We have focused our study thus far on the terminator signals which appear to be consistent with photochemistry effects and on TID wave characteristic analysis. We have collected a set of exceptional TID events over the past nine months and have correlated our calculated wave characteristics with the data from GNSS TEC, digisonde, and SuperDARN in general finding good agreement between our technique and these established methods. While our study still seeks to clarify discrepancies in our data similar to those seen by Chilcote in the original study, the consistency with which our data typically agrees with other methods supports the validity of using AM radio transmissions to track TIDs in addition to other ionospheric phenomena such as the terminator.\ 

Reference: Chilcote, M., et al. (2015), Detection of traveling ionospheric disturbances by medium-frequency Doppler sounding using AM radio transmissions, Radio Sci., 50, doi:10.1002/2014RS005617.

}, author = {Claire C. Trop and James LaBelle and Philip J. Erickson and Shunrong Zhang and David McGaw and Terrence Kovacs} }