The DSES Sudden Ionospheric Disturbance Monitor (SID) detected in September several major solar eruptions – M and X Class Flares. Below are shown graphs of the data from four particular days.
The DSES SID instrument is located in Colorado Springs. It works by listening for a US Navy beacon station in North Dakota, call sign NML, transmitting on the Very Low Frequency (VLF) of 25 KHz. During the day, the D Layer of the ionosphere forms at lower altitudes and attenuates the VLF signal. But during solar flares, VLF signals can more easily pass through the D Layer, and they then get bounced back to the ground from the higher F Layer. The more the solar flare activity affecting our ionosphere, the better the VLF signal from NML propagates to us.
Strong solar flare events show a characteristic spike, and then a “shark tail” as the ionosphere recovers.
At night, the D Layer dissipates, and then the signal from NML usually easily reaches the receiver. At local sunrise, at about 1200 UTC, you can see the effect of the D Layer forming with the sudden drop in reception.
You can see evidence that the F Layer is influenced by the solar flares as well. Notice during the X 8.2 Flare on September 10 that the incoming signal becomes even stronger than during normal propagation at night.
The bottom axis of each graph is Greenwich (UTC) Time. The vertical axis shows the received energy. Individual flare events are identified and annotated in green. Some events occurred during local night.
DSES President Dr. Richard Russel has been measuring signal strengths 0f stations in the Very Low Frequency (VLF) band for the past year, looking for changes in ionospheric propagation due to solar flares. He uses a Sudden Ionospheric Disturbance (SID) monitor small radio telescope. His SID detector is located in Colorado Springs, CO. The measurements are sensitive to the changes in radio propagation at sunrise and sunset.
With his baseline of historical data at sunrise and sunset, he then predicted what could be expected during the August 20, 2017 solar eclipse. He presented his prediction work at the 2017 Society of Amateur Radio Astronomers Annual Conference at NRAO Greenbank, WV on July 25, 2017. His paper was titled, “Ionospheric Reflection Variation During Sunrise and Sunset and Predictions for the 2017 Total Eclipse”.
During the eclipse he made measurements, and found the results matched closely with his predictions. The link presents a summary of his work. Plus it has YouTube links to this and another of his talks at the SARA conference. The second talk is titled, “The Use of Monte-Carlo Analysis to Evaluate Radio Astronomy Source Detection”.
Sky & Telescope has a short, illustrated news item today about high resolution 1H (atomic hydrogen) observations of our galaxy from Australia and Germany. It includes a video showing how the view changes with wavelength due to Doppler shift. I thought this would be good to share; this is what we’ll be looking for with the HI drift scans.
Astronomers Map Millky Way in Incredible Detail – Sky & Telescope
Attached are the August reports for the Radio Jove, located at Plishner, and the SuperSID, which is located at my house.
1) The Radio Jove observing season is closing down with only an hour of observing time a day after sunset. We did get a couple of probable hits.
2) SuperSID did detect an M1.3 flare on 8 August. I also conducted a comparison of the Radio Jove results and the SuperSID results. I found no significant correlation between the two telescopes. The lightning storms this month also affected both telescopes by adding a lot of spurious signals.
I have been in contact with the Radio Jove NASA coordinator. He likes what we are doing and has provided information to improve our Radio Jove system.
DSES will have its first major observing expedition at the Plishner site on 12 – 13 August in conjunction with the Perseid Meteor Shower.
The following radio telescopes will be set up for observing:
1) Hydrogen – on 60 ft dish using Ray’s new feed
2) Radio Jove
3) Meteor Scatter
5) Itty Bitty Telescope
Also a number of optical telescopes will be set up to watch the meteor shower + planet and star observations.
We are also trying to get a solar telescope to do some daytime observations.
Ham radio operators will use the new DSES Club call sign, K0PRT, to make radio contacts. We will have HF antennas plus SHF, UHF, and VHF using the 60 ft dish available.
The setup team will arrive about 1200 on the 12th and start observations around 1700 and throughout the night. Observers should bring thumb drives and observer journals.
Anyone participating should bring sleeping gear and food for the overnight event. The clearing next to the communications van will be available for camping or campers. Recommend anyone sleeping in the bunker bring a cot and sleeping bag.