April 8, 2024 Solar Eclipse QSO Party First Results

The April 8, 2024 HamSCI Total Solar Eclipse QSO Party (SEQP) first results are in! Over 52.7 million radio communications were observed over the continental United States using the PSKReporter, WSPRNet, and Reverse Beacon Network networks. Eclipse effects were observed between 18 to 21 UTC, particularly on the 1.8, 3.5, and 7 MHz bands. These bands all showed enhancement in propagation resulting from the eclipse, suggestive of a reduction in D region absorption. The 14, 21, and 28 MHz bands also showed hints of eclipse impacts. A reduction in communications observed at near-ranges during the eclipse likely results from a reduction in ionospheric electron densities during this time. More analysis to be done in the future!

Special thanks to all the team members and volunteers who made this possible! This work was supported by the U.S. National Science Foundation and NASA.

HamSCI Workshop 2024 Abstract Submission Open

We are looking for presenters for the March 22-23, 2024 HamSCI workshop at Case Western Reserve University in Cleveland, Ohio! The workshop will focus on the theme of Alignments - between the Sun, Moon and Earth; between collegiate amateur radio recreation and STEM curriculum; between data collection and analysis; between professional and citizen science. We are preparing for the solar eclipse of 8 April 2024, for which Cleveland will be in totality. If you would like to present, please visit https://hamsci.org/hamsci2024 to submit an abstract. Abstracts are due by February 10, 2024. Presenters will be notified by March 1, 2024.

SAQ scheduled to air on Alexanderson Day, July 2nd, 2023

By Jonathan Rizzo, KC3EEY

SAQ (callsign SAQ) is a VLF transmitting station located in Grimeton, Sweden and is a UNESCO World Heritage Site operated by the Alexanderson Association. The heart of the transmitter is the Alexanderson Alternator and six antenna towers that are iconic to the site. Twice a year, there is a CW transmission at 17.2 kHz with an inspirational message to listeners all over the world. On Alexanderson Day, July 2nd, 2023, SAQ is scheduled to be on the air. More details can be found here (https://alexander.n.se/en/alexanderson-day-2023/) and contains a tentative schedule and a YouTube live broadcast for those who would like to watch the event live.

HamSCI community members are encouraged to listen to the transmission at 17.2 kHz. There are various ways to listen, including VLF to HF converters for those who want to use their own HF rig; SDRs like the AirSpy R2, KiwiSDR, and others; and broadband VLF receivers/preamps connected directly to computer soundcards using vlfrx-tools, Spectrum Lab, or SAQrx software. If you are able to receive the transmission, please submit a reception report to SAQ via instructions on the website and please make a recording as well. 

In the VLF band, signals propagate the same way as signals in a waveguide due to the Earth-ionosphere waveguide with boundaries formed by the Earth's surface and the D/E layers of the ionosphere. These VLF transmissions are important to science because they give greater insight to VLF propagation as well as the D and E layers of the ionosphere.

Paper on Grape Personal Space Weather Station HF Doppler Observations Published

Dr. Kristina Collins, KD8OXT, is the lead author on a new paper published in the peer-reviewed journal Earth System Science Data entitled Crowdsourced Doppler measurements of time standard stations demonstrating ionospheric variability. The Grape Personal Space Weather Station is a low-cost, high frequency (HF) receiver designed to make precision measurements of signals received from frequency standards stations such as WWV, WWVH, and CHU. Because these standards stations transmit carriers with atomic-clock grade frequency stability, and the Grape receiver achieves similar frequency stability through the use of a GNSS Disciplined Oscillator, variations in the received signal can be attributed to changes in the ionosphere. The new paper demonstrates this in multiple ways, including showing changes in Doppler frequency due to the dawn and dusk terminators, seasonal variations, wave signatures with Medium Scale Traveling Ionospheric Disturbance periods, and the ionospheric response to solar flares. The paper also explains how to access Grape data and the open-source software used to conduct the analysis. The co-author team consists of professionals, students, and HamSCI volunteers, including Kristina Collins KD8OXT, John Gibbons N8OBJ, Nathaniel Frissell W2NAF, Aidan Montare KB3UMD, David Kazdan AD8Y, Darren Kalmbach KC0ZIE, David Swartz W0DAS, Robert Benedict KD8CGH, Veronica Romanek KD2UHN, Rachel Boedicker AC8XY, William Liles NQ6Z, William Engelke AB4EJ, David G. McGaw N1HAC, James Farmer K4BSE, Gary Mikitin AF8A, Joseph Hobart W7LUX, George Kavanagh KB1HFT, and Shibaji Chakraborty KN4BMT. The Grape receivers are the focus of an NSF-funded experiment to study the upcoming 2023 annular and 2024 total solar eclipses. More information on building your own Grape receiver is available at hamsci.org/grape.

Figure from Paper: Heat maps of frequency (a) and amplitude (b) of 10 MHz WWV received by N8OBJ in Macedonia, OH. Each day represents a line of pixels from top to bottom, with corresponding UTC times lined up across the plots horizontally. Diel variation, and the seasonal shift of sunrise and sunset times per Fig. 7, is clearly visible in both plots. A new antenna and preamplifier were installed on 26 August 2021, resulting in higher received power.

Collins, K., Gibbons, J., Frissell, N., Montare, A., Kazdan, D., Kalmbach, D., Swartz, D., Benedict, R., Romanek, V., Boedicker, R., Liles, W., Engelke, W., McGaw, D. G., Farmer, J., Mikitin, G., Hobart, J., Kavanagh, G., and Chakraborty, S.: Crowdsourced Doppler measurements of time standard stations demonstrating ionospheric variability, Earth Syst. Sci. Data, 15, 1403–1418, https://doi.org/10.5194/essd-15-1403-2023, 2023.

N6NC Publishes Propagation Research Articles in QEX

A key component of the HamSCI mission is to encourage amateurs to conduct and share their own research and experiments. Larry Serra N6NC recently published two articles in QEX Magazine from his trans-North Pacific 40m propagation projects: The first, "Why Summer 40m Propagation Is So Good Between Japan and the US Pacific Coast" (QEX SEPT/OCT 2022 p.14), examined 12 years of July JA-US 40m propagation conditions and CW Skimmer results on days of JA domestic CW contests and proposed that the relatively calm water under the almost wall-to-wall summertime North Pacific HIGH pressure centers provided nearly +12dBm enhanced low-angle signal strength due to a reduction of surface reflection absorptions in the 3-ionospheric refraction, 2-sea surface reflection propagation path.

The second article, "A Make-Do Ham Interferometer To Determine Elevation Angles of Arriving RF Signals" (QEX MAR/APR 2023 p.17) explained how a simple digital calculating oscilloscope, measured coax lines and two small, inexpensive PA0RDT active antennas can be used with some math to calculate and confirm the angles of arrival (AoAs) of shortwave signals.

We thank the ARRL for permission to post  "Why Summer 40m Propagation Is So Good Between Japan and the US Pacific Coast" (QEX SEPT/OCT 2022 p.14) to hamsci.org. Full access to QEX is provided as an ARRL membership benefit. Both articles are also translated and published in the Japanese CQ HAM RADIO/QEX MAGAZINE.

Congratulations on your articles, Larry!

QST Article on Measuring the Frequency Accuracy and Stability of WWV and WWVH Published

Mike Lombardi, K0WWX, HamSCI member and Director of the National Institute of Standards and Technology (NIST) Time Realization and Distribution Group published the article Measuring the Frequency Accuracy and Stability of WWV and WWVH in ARRL's March 2023 QST. WWV and WWVH are the United States' National Time and Frequency Standards broadcast stations and are of critical importance to the HamSCI Personal Space Weather Station Project. This article is the follow-on to Mike's 2022 HamSCI Workshop presentation. Special thanks to the ARRL for permission to post this article on hamsci.org.