@proceedings {1057, title = {The DASI2 HamSCI Whistler Catcher VLF Reception System}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {

The Whistler Catcher VLF Reception System is a very low frequency software defined radio (VLF SDR) system. It utilizes an open hardware, open software, and open data design and philosophy to facilitate and promote citizen science in the study of VLF phenomena; including the Earth{\textquoteright}s natural radio emissions, VLF amateur radio transmissions in the 8270 Hz and 5710 Hz bands, and lightning stroke location. The system consists of both hardware and software. The hardware consists of VLF Active Antenna along with a VLF interface box to supply power and interface the signal; a GNSS interface box to provide a pulse per second (PPS) signal for the purposes of frequency calibration and timestamping; a Behringer UMC202HD USB audio interface for data acquisition, and a thin client PC with serial port. The designs of the VLF Active Antenna, VLF Interface Box, and GNSS Interface Box are all open hardware. The software includes vlfrx-tools, an open source software toolkit primarily for the application of VLF signal capturing, calibration, timestamping, filtering, storage, live listening, retrieval, visualization, EbNaut amateur mode decoding, and other signal processing functions in over 30 individual program utilities. It was written by Paul Nicholson G8LMD [SK], a passionate VLF enthusiast to whom the Whistler Catcher VLF Reception System is dedicated.

}, author = {Jonathan Rizzo and Nathaniel Frissell} } @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 {1033, title = {Development of a low-cost magnetometer system for a coordinated space weather monitoring}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {In addition to auroral observations, magnetic field measurements are one of the traditional ground-based methods for observing space weather phenomena. For this purpose, magnetic sensors, known as magnetometers, are widely used in space research. Ground-based magnetometers provide critical information on how solar activity impacts the Earth{\textquoteright}s magnetosphere and the ionosphere. In particular, geomagnetically induced currents (GICs) due to temporal changes in the magnetic field (dB/dt), are a major concern in space weather studies. As part of the 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 approximately 3 nT at a sampling rate of 1 Hz. 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. Once established, a densely spaced magnetometer array will demonstrate space weather monitoring capabilities over an unprecedented spatial extent. Magnetic field data collected by PSWS magnetometers installed at various locations across the United States are presented and compared with data from nearby existing magnetometers, demonstrating that the PSWS instruments provide performance that is well suited for scientific investigations.}, author = {Hyomin Kim and Nathaniel Frissell and Rachel Frissell and David Witten and Daniel Clancy} } @proceedings {1038, title = {Did the Miyako earthquake affect Medium Wave broadcast reception on 9 November 2025?}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {In early November 2025, a group of DXers in northern Japan observed a sharp but temporary attenuation of signal strengths of a number of medium wave broadcast signals in Japan and in northeast China. Within one-half hour, a major earthquake was felt at the listening site. Speculation arose as to whether there could be any connection between the two events. SDR recordings of the entire medium wave band were available from throughout this period, and it was possible to carefully analyze changes in strength of the attenuated signals over time. In addition, by examining the geographic spread of the locations of the transmitters associated with those signals, it was concluded that there was no obvious connection between the earthquake and the observed attenuation. Further investigation revealed that a large solar flare had occurred at the same time as the attenuation. Despite solar flares not normally being perceived as an influence on propagation at medium frequencies because of already existing daytime D-region attenuation, it was found that the progress of the solar flare correlated well with the progress of both the decay and the recovery of the observed signal strengths.}, author = {Satoshi Miyauchi and Nick Hall-Patch} } @proceedings {971, title = {Development of a Contesting and DXing Dashboard for the HamSCI Personal Space Weather Station}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

This project aims to develop a dashboard display specifically for amateur radio HF contesting, DXing, and general operations using data from the HamSCI Personal Space Weather Station as well as potentially adding other local and remote real time data. The HamSCI Personal Space Weather Station is a multi-instrument system designed to measure space weather for both scientific research and amateur radio operations. The core of the PSWS is the RX-888/KA9Q-radio WSPRDaemon-Grape High Frequency (HF) software-defined radio (SDR), capable of capturing and analyzing signals across the 0.3-30 MHz range. While most PSWS development efforts thus far have focused on strictly scientific objectives, this project will aim to make the data available and useful in real time for Ham Radio Operators. The dashboard has a goal of enhancing real-time HF propagation assessments for amateur radio operators. By decoding WSPR spots and integrating with external space weather observations, this dashboard will provide propagation insights on an individual station basis. The dashboard will also contribute to a larger understanding of both localized and global HF conditions. This should allow amateur radio operators to optimize their transmissions based on real-time ionospheric conditions, which can help improve contesting efficiency and DXing success. This project will involve the HamSCI Community, the Frankford Radio Club, and W3USR. This project aims to advance amateur radio capabilities and strengthen science contributions to space weather research.

}, author = {Owen Ruzanski and Nathaniel Frissell and Ray Sokola and Bud Trench} } @proceedings {974, title = {Discovering Amateur Radio}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The author\ shares his vision for a more active and engaged Amateur Radio Service, exploring how the ham radio community can inspire others to develop a deeper understanding for wireless communications. Through personal stories, ARRL initiatives, and a spotlight on some of the brightest areas of amateur radio activity, Inderbitzen will illustrate\ how the service acts as a "sandbox" for introducing the public to the world of radio, while nurturing the next generation of innovators in radio science and technology.

}, author = {Robert Inderbitzen} } @proceedings {939, title = {Distributional Characteristics of Short-Term 2022 20-Meter Sequential Matched WSPRDaemon Noise Observations}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Understanding the characteristics and structure of one{\textquoteright}s data is critical for effective data analysis. Currently, WSPRDaemon data are being used in background noise level, HF propagation, Doppler shift, and correlational studies. Here we use Exploratory Data Analysis (EDA) on short-term (2-minute), sequential observations of WSPRDaemon observations to gain insights into the distributional characteristics of the data prior to more advanced modeling or analytical procedures. Our findings uncovered data outliers and puzzling distributional characteristics. \ While consistent in their presence, these anomalies were unique from one receiving station to the next. These findings warrant further consideration and explanation before researchers invest time attempting more complex analytic procedures. \ They also strongly suggest that a parallel data base of meta-data for the receiving stations would be extremely helpful for future studies.\ 

}, author = {Robert Gerzoff and Gwyn Griffiths} } @proceedings {864, title = {Design and 3D Printing of the Grape 2 Enclosure}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

This poster presents the design of the 3D printed enclosure for the Grape 2 Personal Space Weather Station HF Doppler Receiver.

}, author = {Majid Mokhtari and John Gibbons and Nathaniel A. Frissell} } @proceedings {877, title = {Detection of SuperDARN-Observed Medium Scale Traveling Ionospheric Disturbances in the Southern Hemisphere}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Traveling Ionospheric Disturbances are quasi-periodic variations in the plasma that exist in the upper atmosphere and they impact the propagation of radio waves. Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are defined as TIDs which travel at 100-250 m/s and have periods within the 1 hour range. Previously, most of the existing research has focused on MSTIDs in the Northern Hemisphere. This project seeks to determine whether there is enough data available to recognize seasonal trends in MSTID occurrence in the Southern Hemisphere. Currently, we have found some success in applying the PyDarnMusic algorithm to identify periods of high and low MSTID activity in the southern hemisphere in SuperDARN and have had success in replicating an existing study on the Falkland Islands radar. Going forward, we hope to refine the techniques which were originally used to identify MSTIDs in the Northern Hemisphere for use on the Southern Hemisphere in order to gain a better understanding of their climatology.

}, author = {James P. Fox and Joseph Klobusicky and Nathaniel A. Frissell} } @proceedings {865, title = {Development of Back-End Software for the Grape 2}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

This poster showcases several software tools developed to support the development and operation of the main Grape 2 system. G2console is a terminal-based interface that communicates with the data collection system, providing users with valuable information such as software versions, amplitude, frequency, GPS, and magnetometer metrics for viewing and diagnostics. GrapeSpectrogram is a data processing script that generates Dopplergrams, aiding developers in validating the system{\textquoteright}s operation. Additionally, we will discuss future project developments, such as integration with the Linux GPS background service (gpsd) to provide accurate timing to the Raspberry Pi, and DigitalRF as a more efficient method of data storage.

}, author = {Cuong Nguyen and William Blackwell and John Gibbons and Nathaniel Frissell} } @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} } @proceedings {624, title = {Detecting Large Scale Traveling Ionospheric Disturbances using Feature Recognition and Amateur Radio Data}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

A Large-Scale Transient Ionospheric Disturbance (LSTID) is a traveling perturbation in ionosphere electron density with a horizontal wavelength of approximately 1000 km and a period between 30 to 180 minutes. These can be detected by SuperDARN HF radar and GNSS Total Electron Content measurements. Recently it has been discovered that these can also be detected in amateur (ham) radio signal reports, which are now being generated in vast numbers by operators world-wide. A machine-learning technique was developed to find patterns in these data that indicate the presence of LSTIDs using an object detection technique.

}, author = {William D. Engelke and Nathaniel A. Frissell and Travis Atkison and Philip J. Erickson and Francis Tholley} } @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} } @conference {405, title = {Direction Finding: Analog and Digital Applications (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Amateur radio encompasses the building of hardware, the programming of different communications devices, and the integration of hardware and software. One popular amateur pastime, radio direction finding, requires a fair amount of technical knowledge to include antenna design and radio wave propagation in the VHF radio band. Participants use specialized directional antennas to find a bearing for an unknown signal. An intense understanding of antenna radiation patterns can be used to accurately identify the source of this signal. Simulation on computer programs through test equipment helps hobbyists fully understand the characteristics of their direction finding devices. However, direction finding can be approached from the electronic realm as well as the physical realm. Instead of just directional antennas, one can utilize Digital Signal Processing (DSP) with software-defined radios to locate and identify unknown signals. Programs such as Matlab and GNURadio combined with hardware such as the KerberosSDR and HackRF fully utilize this avenue of signals intelligence. The dichotomy between {\textquotedblleft}physical{\textquotedblright} direction finding and digital signal processing provides an interesting argument for use of one over another. While antenna-focused direction finding relies on vast technical knowledge of propagation and gain, computer- based direction finding similarly requires computational knowledge with various signals and mathematical techniques. In addition, the two techniques serve almost divided purposes: while analog direction finding can locate a signal real-time, DSP can be used to deconstruct and decode signals after their interception. One technique does not outweigh the other, as both have different use cases and applicability. This presentation will outline the basic approach to each avenue of direction finding and the advantages each technique holds. Hobbyists should learn from both techniques of direction finding to gain applicable skills in electromagnetic wave theory.

}, author = {Nolan Pearce} } @conference {300, title = {Digital Mobile Radio Support of High Altitude Balloons for a 2017 Total Solar Eclipse Cloud Formation Experiment}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Edge of Space Sciences (EOSS, eoss.org) is a Denver, Colorado based non-profit organization that promotes science and education by exploring frontiers in amateur radio and high altitude balloons. Two years prior to the total eclipse of the sun (21AUG17) we were approached by Colorado University Boulder Space Grant Consortium \& NASA about flying a pair of balloons with high resolution cameras for the eclipse. They wanted a specific altitude (85,000 foot) at the total eclipse for their cameras which was going to occur in Southeastern Wyoming. They were looking for cloud formation during the eclipse and this was coordinated with three mobile Doppler radar trucks. We did a survey of the predicted landing zone (Southeastern Wyoming/Western Nebraska) and found that there was little to no cellular service and zero amateur repeater coverage. Terrain considerations negated the use of 2M or UHF simplex and HF didn{\textquoteright}t have the right propagation. We designed a 4 site Motorola Digital Mobile Radio (DMR) system using IPSite connect with a combination of microwave and VSAT backhaul. We coordinated 4 sets of Emergency Special Event UHF DMR repeater frequencies from the Wyoming Frequency coordinator (W7QQA, Leonard Pearce). We located 4 sites and negotiated with the owners (including the use of the City of Torrington, Wyoming water tower) and ran Longley Rice coverage studies from each location. We rented and programmed 10 Motorola 4550 mobiles and installed them in the tracking and recovery crew vehicles and trained then on how to use them. We programmed up the mobiles with roaming lists and the system {\textquotedblleft}pinged{\textquotedblright} every 15 seconds (1/4 mile at 60 MPH). All the tracking and recovery teams had to do was push the PTT and wait for the {\textquotedblleft}go tone{\textquotedblright}. We used the second time slot to communicate with the Goshen County Sheriff Department who{\textquoteright}s main 911 dispatcher during the eclipse was a Ham for use in the event there was a public safety issue in a location without cell coverage. We built and tested all of the repeaters and duplexers and double conversion UPS and kitted them up together with the feed lines and antennas. One site used Telewave ANT450D6 antenna set to cardioid pattern to put the RF energy where we needed it. Our Comms team of 6 installed the system over one weekend a week before the event. We did a {\textquotedblleft}drive test{\textquotedblright} and determined that our Longley-Rice pattern studies were very conservative and the system coverage significantly exceeded the predicted coverage. The system covered more than 7,600 square miles of Southeastern Wyoming.

}, author = {Michael Pappas} } @conference {294, title = {Doppler Shift from Earth-Orbiting Satellites}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSC}, organization = {HamSC}, address = {Cleveland, OH}, abstract = {

Doppler shift, which is easily observable as a change in frequency, is due to a change in the phase path between an emitter and observer over time.\  The changing phase path contains information about the position of the emitter as well as the propagation medium.\  This presentation describes an effort to estimate the Doppler shift of the now-defunct VO-52 ({\textquotedblleft}HAMSAT{\textquotedblright}) satellite at 145 MHz and theoretical concepts of orbit determination by trilateration.\  It is similar to work performed in the West during the early weeks of the Space Race that determined the orbit of Sputnik-I and led to the development of the satellite Doppler navigation (TRANSIT) technique.

}, author = {Michael S. Miller and Ethan S. Miller} } @conference {209, title = {Developing a Solar Eclipse Simulation for Greater Good}, booktitle = {ARRL and TAPR Digital Communications Conference}, year = {2017}, month = {09/2017}, address = {St. Louis, MO}, abstract = {

This paper presents our methodology for simulating the upcoming total solar eclipse that will be taking place on August 21, 2017. By taking advantage of a high-performance distributed computing cluster as well as a number of third-party scientific computing libraries we were able to efficiently simulate a large number of HF amateur radio contacts before, during, and after the upcoming eclipse. The data generated from the simulations allows us to peek into how the amateur radio community and radio propagation as a whole will be affected in preparation for the actual eclipse.

}, url = {https://www.tapr.org/pub_dcc.html}, author = {J. S. Vega and N. A. Frissell and J. D. Katz and J. D. Huba} } @conference {54, title = {Dayside Ionospheric Response to X-Class Solar Flare Events Observed with Reverse Beacon Network High Frequency Communication Links}, booktitle = {Virginia Tech REU Symposium - Poster Presentation}, year = {2015}, month = {07/2015}, publisher = {Virginia Tech REU Program}, organization = {Virginia Tech REU Program}, address = {Blacksburg, VA}, url = {http://hamsci.org/sites/default/files/article/file/Csquibb_REU2015_Poster.pdf}, author = {Carson O. Squibb and Nathaniel A. Frissell and J. Michael Ruohoniemi and Joseph B. H. Baker and Robyn Fiori and Magdalina L. Moses} }