@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 {1045, title = {Personal Space Weather Station Observations of the Gannon Geomagnetic Storm}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {The geomagnetic storm known as the Gannon Storm took place from 10-13 May 2024. Classified as a G5 geomagnetic storm, the Gannon Storm was the most extreme event of its kind to occur in the past two decades. Space weather events of this magnitude have significant impacts on orbiting satellites, navigation systems, power grids, and communications. Particularly, geomagnetic storms are known to disrupt technologies that utilize the high frequency (HF) portion of the radio spectrum. The aim of this study is to understand the Gannon Storm{\textquoteright}s effects on HF propagation. Using the Ham Radio Science Citizen Investigation{\textquoteright}s network of personal space weather stations (PSWSs), Doppler shift data gathered during the Gannon Storm is examined and compared against data collected on days with quieter geomagnetic conditions. PSWS receivers detected elevated Doppler shifts among traveling HF signals and more interruptions to the signals than is typical. Studying the Gannon Storm{\textquoteright}s effects on HF propagation can inform how technologies that rely on these frequencies may be better equipped against similar extreme space weather events in the future.~~~}, author = {Rebecca Potter and Nathaniel Frissell and Gwyn Griffiths and Kuldeep Pandey} } @proceedings {1037, title = {Solar Eclipse Through Ham Radio: What the Bands Revealed}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, author = {Kuldeep Pandey} } @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 {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} }