Tag Archives: 2024 Solar Eclipse

Rich’s propagation observations during the total solar eclipse

Many thanks to SWLing Post contributor, Rich Stahl, who writes:

In Ocean View NJ, our eclipse started at 2:08, 3:23 totality, and ended 4:35. We have a daytimer here on 1020, WWAC, at 1900 watts, and I was curious if KDKA, at 50kw, also on 1020, would have any presence during the event. I used my Tecsun PL330, on the internal ferrite antenna, and did a band scan 530-1710 every fifteen minutes to see what it would capture. From 2:15 up to the 3:45 scan, the radio captured between eight and ten signals per scan. Up to this point, the sun still had the D layer fully ionized. But after the mid point, the 4:00 scan had 19 captures, the 4:15 scan had 38, and the 4:30 scan had 36. The D layer had obviously de-ionized considerably. The very next scan, at 4:45, captures back down to 9. The sun was back in business. And never did I hear a peep out of KDKA.

Rich Stahl
WR3V
Ocean View, NJ

Thank you for sharing your findings, Rich! Perhaps others can comment with their observations as well.

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How to DX the 2024 Solar Eclipse!

Many thanks to SWLing Post contributor, Nick Hall-Patch, who shares the following article originally published in the IRCA’s DX Monitor:


2024 Solar Eclipse DXing

by William Scott, WE7W

DXing the mediumwaves promises to be an exciting event on April 8 during the 2024 total solar eclipse.    I’ve been mulling over the DX possibilities a lot lately and have come to some conclusions. I think it boils down to three promising DX scenarios:

  • Scenario 1. For those who live within or very near the path of totality (see Figure 1), I believe best chances of DX would be first to listen to your southwest, along the path where totality is approaching. Darkness will already have happened in that direction, and a certain amount of residual de-ionization of the ionosphere will still remain. After the point of totality passes your location, I would swing my attention to the northeast.
  • Scenario 2. For those living within about 800 km (or about 500 miles) of the path of totality I believe best chance would be a perpendicular path across the totality path to a point roughly equidistant on the other side. This puts the signal reflection point right at the center of the totality path, or the deepest point of darkness.
  • Scenario 3. For those living more than about 800 km from the path of totality I believe best chance would be along a line from your receiving site to a perpendicular intersection to the totality path. This should define the greatest shaded path.

I think that scenarios #1 and #2 have the best possibility for DX.

Figure 1 (Click to enlarge)

Across the U.S. and Canada, from its entry at Texas to its exit through NE Canada and into the Atlantic Ocean, the totality path width varies from a maximum of 199 km at U.S. entry to about 160 km at Atlantic exit, or 123 to 99 miles.

Important to keep in mind – skywave signal strength analysis is based almost entirely on the condition of the ionosphere at the reflection point, not at the receiving site. For single hop propagation, normally the reflection point is at the halfway point to the station along the great circle route.    That 800 km distance from the totality center I wouldn’t hold as gospel. I’m throwing that figure out as a point where scenario #2 may start to transition to scenario #3.

Timing is of the essence for DXing. The shadow velocity exceeds 1000 mph, increasing from 1587 miles per hour at Eagle Pass, Texas to 3176 mph at Houlton, Maine. You may have only minutes to DX.     I’ll be in Rochester, NY at the time of totality, and we are right at dead center. I’ll be scenario #1. My plan is to listen to my southwest initially, where totality is approaching. I’ll be listening particularly for WLW-800 in Cincinnati, OH, WHAS-840 in Lexington, KY, and others along or near that path.

Scenario #2 possibly holds the most promise. Calculate your distance to the path center line and look for stations on a direct line across the totality path and at an equal distance on the opposite side of the path from you. One such scenario might be WSB-750, Atlanta to a reception point in northwestern Illinois, central Iowa, or southern Wisconsin or southern Minnesota. Many possibilities on cross-paths exist here. I feel best results would be with a signal path that crosses the path of totality closest to 90 degrees.

A question was raised about the possibility of DX from Spokane, Washington, an extreme distance from the path of totality. That particular scenario would be scenario #3, more than 800 km to the path of totality. Maximum obscurity should be when northeast Texas (let’s say the Dallas area) is experiencing full totality, as the great circle line to the totality path intersects at approximately 90 degrees to the line at that point. This would be at about 1848 UTC. I would listen for any signals along a great circle path between Spokane to anywhere from the Dallas area and northward.     Obviously, Spokane to Dallas is an extremely long one hop path, at about 2450 km. At that distance, the reflection point is near Denver, which will have a solar obscuration of 65.1% at maximum.

A Dallas area reception would be next to impossible I would think, but there are many more stations along that great circle path one could try for. Closer stations will obviously move the reflection point closer and start to reduce the solar obscurity. I did a scan along that path and there are some 340 stations within 200 km either side of the line of the great circle path between Spokane and Dallas.

A presumed Scenario #4.

Another scenario was suggested by Nick Hall-Patch, that of reception parallel to the path of totality and outside the 100% totality band. The 2017 solar eclipse across the northern part of the U.S. was DXed extensively and produced some interesting results, which are well documented in IRCA Reprints.  Check their document repository here:

http://dxer.ca/images/stories/2019/irca-reprint-index.pdf

Nick reports: “The receptions of KSL-1160 described in IRCA Reprint # G-096 showed the results of 3 DXers listening across the path of the eclipse (Scenario #2), but the fourth, Dave Aichelman, was monitoring KSL from a location parallel to the eclipse path ( sort of Scenario #1?) and got very good enhancement as well.”    We might name this “Scenario #4”.

I checked out # G-096, that documents the KSL reception from the solar eclipse of 2017. It looks like the Dave Aichelman (at Grants Pass, OR) reception of KSL had a mid-path reflection point of about 95% solar obscurity. The distance was 971 km (602 miles). Graphing KSL, I see it has a nice fat low angle takeoff and impressive skywave strength at 900 km, some 1.3 mV/m for that distance. (ed. note: A map of fractional solar obscuration is in Figure 2, easily converted to the percentage figures quoted in this article. )

Better yet, the article indicated Aichelman also received XEPE-1700 across the Mexican border from San Diego too. That was a mid-point reflection obscurity of only about 83% as far as I can deduct from the maps. The distance was 1238 km (769 miles). The mid-path reflection point there was in the neighborhood of 700 km from the central path of totality.

So, DX is indeed possible where both the station and the receiver are off center from the totality path. It’s looking like anything from at least 80% obscurity at mid-path reflection may have some real possibilities, particularly if you are at the end nearest the path of totality. Lower obscurities, perhaps down to 50% or so may even produce results.

Check out these links.

https://nationaleclipse.com/cities_partial.html

https://eclipse.gsfc.nasa.gov/SEpath/SEpath2001/SE2024Apr08Tpath.html

https://eclipse2024.org/eclipse_cities/statemap.html

Using my pattern mapping program which has extensive area search capability, I’ve compiled a list of all US and Canadian stations that fall within the 2024 Solar Eclipse path of ~100% totality. There are 456 stations. Results are drawn from the March 20 FCC LMS database and Industry Canada database. Sorry I don’t have Mexico available.

If you would like this list, download from this link. https://www.mediafire.com/file/125ih5yrmw4puib/2024-eclipse-stations-by-longitude.zip/file

Across the US and Canada, from its entry at Texas to its exit through NE Canada and into the Atlantic Ocean, the totality path width varies from a maximum of 199 km at US entry to about 160 km at the Atlantic exit off Newfoundland, or 123 to 99 miles.   456 stations are found in this eclipse path. I purposely set the path width to 210 km from start to finish. This gives a few km slop on both sides of the 100% totality path for good measure.

Unzip the downloaded .ZIP file, where you will find 3 files. The stations in each file are sorted by longitude, from west to east. This gives us the progression of the eclipse path, with the eclipse starting at the first station in the list and ending with the last station.

File #1 is a simple text file.

File #2 is in .CSV format. You can easily input it to an Excel file.

File #3 is in .HTML format. It includes links to each station’s Google Map latitude-longitude coordinates for the satellite view of the transmitter tower array.

Another link takes you to the FCC AM Query link for that station.  I hope these files are beneficial. There should be many propagation path possibilities outside of this list as well.

(reprinted from the author’s blog at https://radio-timetraveller.blogspot.com/ )

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Further sources of information concerning the eclipse include the following websites:

http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2024_GoogleMapFull.html?Lat=43.66400&Lng=-76.13690&Elv=88.0&Zoom=6&LC=1

(Clicking anywhere on this map page will give all the information you need about obscuration, length of eclipse etc.at a given location).  Also:

https://www.greatamericaneclipse.com/april-8-2024

https://eclipsewise.com/2024/2024.html

Animations of the path of the eclipse versus time can be seen at:

https://eclipsewise.com/solar/SEanim400/2024_04_08_TSE_400px.gif

http://7dxr.com/4all/100km8Apr-movie–Frissell-HamSCI.mp4

The latter is particularly interesting, as it shows the moon’s shadow at 100km height above the earth, an area of special interest to DXers, as it is the lower edge of the E-region of the ionosphere.  Note especially that as the eclipse ends over the North Atlantic Ocean, that there is a temporary darkness path between Europe and North America, because night will already have fallen in Europe.  So will there be blips of TA DX in eastern North America as the eclipse passes by?   Listen, and find out!

Finally, our DX could be of interest to ionospheric physicists also.   The rapidly changing listening conditions will be indicating a similarly turbulent ionosphere, and DXers’ documenting those listening conditions through SDR recordings could provide information that will be useful to scientists who want to gain a better understanding of the Earth’s ionospheric dynamics.

HamSCI is an organization of volunteer citizen-scientists and professional researchers who study upper atmospheric and space physics, and will be interested in examining MW DXers’ wideband SDR recordings made during the eclipse period, and indeed, in having DXers assist with HamSCI’s research. (see https://hamsci.org/eclipse.  Especially if you are an amateur radio operator, there are several other ways that you might also contribute to the project.)

(This first appeared in IRCA’s DX Monitor and is used with permission.   See https://www.ircaonline.org/default.php for club details)

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Only One Week To Go: HamSCI Presents the Solar Eclipse QSO Party!

Many thanks to SWLing Post contributor, Edward Efchak, who shares the following announcement:


ONE WEEK TO GO!  SAVE THE DATE!!

Monday, April 8TH!!  

HamSCI Presents the Solar Eclipse QSO Party – April 8, 2024

Join with thousands of your fellow amateurs as part of the largest crowd-sourced event for ham radio scientific exploration ever!  The SEQP is part of The Festivals of Eclipse Ionospheric Science and is for learning more about how the ionosphere works. Use any mode, any band for all or part of the day!  Participation can be from everywhere – you need not be near the path of the eclipse to contribute valuable data by participating.

Or just get on the air and help provide the data to better understand the ionosphere.

Save the date – Monday, 8 April 2024

Get on the air! 1400-2400 UTC

Do it for science!! Any band/any mode (except the WARC bands)

HamSCI serves as a means for fostering collaboration between professional researchers and amateur radio operators. It assists in developing and maintaining standards and agreements between all people and organizations involved. Its goals are to advance scientific research and understanding through amateur radio activities and encourage the development of new technologies to support this research.

For more information about HamSCI, please visit the HamSCI website (www.hamsci.org) . For more information about the Festivals of Eclipse Ionospheric Science educational opportunities for the amateur community and the public please visit our information pages.

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RAC: Canadian Amateurs Invited to Participate in Solar Eclipse Project

Many thanks to SWLing Post contributor, Richard, who shares the following announcement from the RAC:


Contribute to Eclipse Science and History: Research Propagation with Your Receiver!

March 5, 2024 – 

The Case Amateur Radio Club W8EDU of Case Western Reserve University in Cleveland, Ohio is excited to invite Canadian Amateurs to participate in the upcoming CHU Eclipse Data Collection Project!

We will be monitoring the reception of the Canadian time standard CHU before, during, and after the eclipse to measure the recombination time of the ionosphere. In other words, we know that the ionosphere changes in response to the presence of UV radiation in the sun by ionizing during the day and ‘de-ionizing’ at night (which is why many frequency bands propagate differently during the day and the night).

We understand how the ionosphere changes over a normal 24-hour period in response to the relatively slow transition from daytime to night time, but want to learn more about how it changes over a much shorter period (which is what the eclipse provides). We want you to help!

Our goal is to study how the eclipse affects radio wave propagation, helping us understand the ionosphere’s recombination time. To achieve this, we need your help recording Canada’s time standard station CHU for two weeks surrounding the April 8th eclipse. Anyone with a KiwiSDR or a rig capable of interfacing with analysis/recording software like Fldigi is encouraged to join the effort!

This project has already garnered enthusiastic support from various communities, including the American Radio Relay League, the Radio Amateurs of Canada, and the Ham Radio Citizen Science Investigation HamSCI.

We have over 20 stations across the continent participating, from universities and high schools to representatives from the Radio Amateurs of Canada and even a station in Mexico!

To join us and contribute valuable data, simply visit our website and follow the instructions (https://w8edu.wordpress.com/chu-eclipse-data-collection/) to set up your station and notify us about your participation.

Please reach out to [email protected] if you have any questions or comments.

Adam Goodman W7OKE, President, Case Amateur Radio Club
David Kazdan AD8Y, MD, PhD, Faculty Advisor, Case Amateur Radio Club
Chistian Zorman, PhD, Faculty Advisor, Case Amateur Radio Club, Associate Dean for Research, Case School of Engineering

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2024 Eclipse: HamSCI Roundtable Events

Many thanks to SWLing Post contributor, Ed Efchak (WX2R), who shares the following announcement:


The Solar Eclipse Is One Month Away!

Learn How You Can Participate in Two HamSCI Roundtable Events

The last total solar eclipse across North America for twenty years will occur on Monday, April 8th. Hams across North America are asked to participate in learning more about how the ionosphere functions by getting on the air to help scientists in a series of ionospheric experiments.

Connect with HamSCI members and curious hams on Wednesday, March 27 at 8PM (Eastern) / 5PM (Pacific)*, or that same day at 10PM (Eastern) / 7PM  (Pacific)* for a Zoom presentation on HamSCI’s Festivals of Eclipse Ionospheric Science (FoEIS).  The presenters will take your questions during the 30-minute presentations.

The link to these presentations is here: https://scranton.zoom.us/j/286316405?pwd=QWdwMlFPbDlYeXg5ZDg1dmYzeFdCUT09#success

The program will start by covering HamSCI’s basis and purpose, quickly moving into why we are conducting experiments, how hams and SWLS can participate, and what we hope to learn from the event.  Along the way, we will discuss why the science behind the events is important to users of the high frequency radio spectrum – including amateur radio operators!

Learn about the HamSCI’s eclipse-focused operating events:

Solar Eclipse QSO Party (SEQP)

Gladstone Signal Spotting Challenge (GSSC)

Medium Wave Recording Event

Time Delay of Arrival (TDOA) Event

Grape 1 Doppler Receiver project

…and more!

There is no need to pre-register, create an account or log into any site. Simply follow this link at the date and times above to be taken to a Zoom meeting room, hosted by HamSCI:  HamSCI FoEIS Roundtable Zoom Link

Join us on March 27th!!   Get on the air April 8th!!

HamSCI serves as a means for fostering collaboration between professional researchers and amateur radio operators. It assists in developing and maintaining standards and agreements between all people and organizations involved. Its goals are to advance scientific research and understanding through amateur radio activities and encourage the development of new technologies to support this research.

For more information about HamSCI, to join our mailing list, or participate in our work, please visit us at www.hamsci.org.

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Eclipse Radio: Several NASA-Funded Science Projects

Many thanks to SWLing Post contributor, David Iurescia, who shares the following article via NASA:


The Aug. 21, 2017, total solar eclipse douses Umatilla National Forest in shadow, darkening the sky and rimming the horizon with a 360 degree sunset. Credit: NASA/Mara Johnson-Groh

NASA-Funded Science Projects Tuning In to ‘Eclipse Radio’ (NASA)

On April 8, 2024, a total solar eclipse will cross parts of the United States. For millions of people along the path of totality, where the Moon will completely cover the Sun, it may feel like an eerie daytime darkness has descended as temperatures drop and wind patterns change. But these changes are mild compared to what happens some 100 to 400 miles above our heads in an electrically conductive layer of our atmosphere known as the ionosphere, where the “false night” of an eclipse is amplified a hundredfold. Three NASA-funded experiments will investigate the eclipse’s effects on the ionosphere through the power of radio, a technology well suited to studying this enigmatic layer of our atmosphere.

Whether you’ve heard of the ionosphere or not, you’ve likely taken advantage of its existence. This electric blanket of particles is critical for long-distance AM and shortwave radio. Radio operators aim their transmitters into the sky, “bouncing” signals off this layer and around the curvature of Earth to extend their broadcast by hundreds or even thousands of miles.

The ionosphere is sustained by our Sun. The Sun’s rays separate negatively charged electrons from atoms, creating the positively charged ions that the ionosphere is named for. When night falls, over 60 miles of the ionosphere disappears as ions and electrons recombine into neutral atoms. Come dawn, the electrons are freed again and the ionosphere swells in the Sun’s illumination – a daily cycle of “breathing” in and out at a global scale.

A total solar eclipse is a scientific goldmine – a rare chance to observe a natural experiment in action. On April 8 the three NASA-funded projects listed below are among those “tuning in” to the changes wrought by a blotted-out Sun.

SuperDARN

The Super Dual Auroral Radar Network, or SuperDARN, is a collection of radars located at sites around the world. They bounce radio waves off of the ionosphere and analyze the returning signal. Their data reveals changes in the ionosphere’s density, temperature, and location (i.e. movement).

The 2024 eclipse will pass over three U.S.-based SuperDARN radars. A team of scientists led by Bharat Kunduri, a professor at the Virginia Polytechnic Institute and State University, have been busy preparing for it.

“The changes in solar radiation that occur during a total solar eclipse can result in a ’thinning’ of the ionosphere,” Kunduri said. “During the eclipse, SuperDARN will operate in special modes designed to monitor the changes in the ionosphere at finer spatiotemporal scales.”

Kunduri’s team will compare SuperDARN’s measurements to predictions from computer models to answer questions about how the ionosphere responds to a solar eclipse.

HamSCI

While some experiments rely on massive radio telescopes, others depend more on people power. The Ham Radio Science Citizen Investigation, or HamSCI, is a NASA citizen science project that involves amateur or “ham” radio operators. On April 8, ham radio operators across the country will attempt to send and receive signals to one another before, during, and after the eclipse. Led by Nathaniel Frissell, a professor of Physics and Engineering at the University of Scranton in Pennsylvania, HamSCI participants will share their radio data to catalog how the sudden loss of sunlight during totality affects their radio signals.

This experiment follows similar efforts completed during the 2017 total solar eclipse and the 2023 annular eclipse.

“During the 2017 eclipse, we found that the ionosphere behaved very similar to nighttime,” Frissell said. Radio signals traveled farther, and frequencies that typically work best at night became usable. Frissell hopes to continue the comparison between eclipses and the day/night cycle, assessing how widespread the changes in the ionosphere are and comparing the results to computer models.

RadioJOVE

Some radio signals don’t bounce off of the ionosphere – instead, they pass right through it. Our Sun is constantly roiling with magnetic eruptions, some of which create radio bursts. These long-wavelength bursts of energy can be detected by radio receivers on Earth. But first they must pass through the ionosphere, whose ever-changing characteristics affect whether and how these signals make it to the receiver.

The RadioJOVE project is a team of citizen scientists dedicated to documenting radio signals from space, especially Jupiter. During the total solar eclipse, RadioJOVE participants will focus on the Sun. Using radio antenna kits they set up themselves, they’ll record solar radio bursts before, during, and after the eclipse.

During the 2017 eclipse, some participants recorded a reduced intensity of solar radio bursts. But more observations are needed to draw firm conclusions. “With better training and more observers, we’ll get better coverage to further study radio propagation through the ionosphere,” said Chuck Higgins, a professor at Middle Tennessee State University and founding member of RadioJOVE. “We hope to continue longer-term observations, through the Heliophysics Big Year and beyond.”

Find out more about the April 8, 2024, solar eclipse on NASA’s eclipse page.

By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.

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