Feb 112023
 

It looks like I got the SID detector remounted just in time. The Sun is coming out of a long, low solar minimum. It is now starting to show an increasing level of activity as evidenced by the number of sunspots starting to show up in the Sun’s photosphere.

I originally installed the observatory’s SID detector at the end of 2018 just as solar cycle 24 was winding down. Even at cycle 24’s maximum, the sunspot count was noticeably low with an even lower count of flares. There was some activity but none that effected the ionosphere enough that my equipment noticed any changes. Then at the end of 2020 I had to take the detector offline due to renovations in the observatory office.

With the solar activity finally starting to increase, I made the effort to finish the reinstallation of the SID equipment. This involved moving the antenna outside and dealing with the complications of routing the cables into the office. I finished that effort on the 17th of January. Even with the number of sunspots and associated flares climbing I still didn’t see any response from my equipment. That changed this past week. There was an M class flare on the 8th that just bumped up the signal I was monitoring. Today however, was the first X class flare that I noticed since I originally installed the equipment.

The upper half of the chart shows data reported by the GOES 16 spacecraft as a white line. The same chart shows the signal received by the PTO from the Navy’s NAA VLF transmitter as a blue line. As you can see, even though this was a minimal X class flare (1.1), the impact on the strength of the transmission received immediately increased. A subsequent M class flare resulted in a proportionally smaller increase.

The sunspot count anticipated for cycle 25 is already ahead of prediction. Cycle 25 may be one to pay close attention to. The SID detector data is available using the Observatory->Solar Conditions menu.

 Posted by at 23:14
Dec 162018
 

I’ve been looking to add radio astronomy capabilities to the PTO. As a first step out of the optical arena I have acquired a kit to assemble a radio receiver that monitors selected VLF radio frequencies. By monitoring received signal strength you can detect changes in Earth’s atmosphere due to the tremendous energy put out by solar flares. These atmospheric changes are known as SIDs (Sudden Ionospheric Disturbances).

The kit was designed by the Stanford Solar Center at Stanford University and supported and sold by the Society of Amateur Radio Astronomers (SARA). Although it is a kit, the only assembly necessary was to construct the structure to support the antenna and winding the antenna wire onto the support.

SID monitor receiver and cabling.

SID monitor antenna.

The signal measurements made by the monitor are saved and automatically sent daily to the Stanford Solar Center. The measurements will be sent monthly to the AAVSO manually. I have written software that combines the strength measurements, data downloaded from the GOES-15 weather satellite, and NASA solar flare event reports to generate the chart below. The daily chart is on the Observatory->Solar Conditions menu.

PTO solar conditions chart for Dec 15, 2018. Notice the class B1.0 flare indicated at about 1349(UTC).

 Posted by at 17:26