[Duffy]

Hi all,

Just run across an article on today's "Spaceweather.com" about how the energy released during the 25th April Nepal Earthquake was detected in the Ionosphere using a GPS receiver. The receiver was in a neighboring region to Nepal, and though my system was off at the time, I did find a fellow monitorist in France, who did record a disturbance in one of his traces as the following image shows.

   

Like myself, he monitors several stations, the unaffected one's I've removed for better clarity, which leaves the red trace of TBB (Turkey). Note the time TBB goes off and on again, the quake occured at 06:11 UT, and TBB is the closest station he monitors to Nepal.

My system was off because I was still in bed at the time, Besides, all my gear is pointing at the ground .

Duffy,

[Skywise]

Thanks for sharing that graph. Very interesting.

Brian

[Island Chris]

Hi Duffy,

What is the Green trace? Also, I don't know how to read the Red trace: Is the part where it is smooth when the transmitter is off?

By the way, real ionosphere monitoring people do not sleep (Kidding).

Chris

[Duffy]

(05-03-2015, 10:46 AM)Island Chris Wrote: Hi Duffy,

What is the Green trace? Also, I don't know how to read the Red trace: Is the part where it is smooth when the transmitter is off?

By the way, real ionosphere monitoring people do not sleep (Kidding).

Chris

Hi Chris,

The green trace is a satellite enviroment signal, this guy's using different software to mine, which allows him to receive real-time satellite data from the GOES network orbiting Earth. You'll notice a couple of bumps in the trace with numbers over them, these are solar flares that the satellite has detected and relayed to his monitor.

The Red trace is showing that the transmitter was on during the period the image shows, the difference is VLF signals act differently during the night compared to daytime. The Ionosphere is made up of four main componants called the D,E,F1 and F2 layers, the D-layer is the lowest part of the Ionosphere and it's existance is totally reliant on UV radiation from the Sun. The D-layer is also the main componant that VLF signals use to propogate round the globe during daylight hours, basically bouncing between sky and Earth to reach their destination, it also has the effect of stablising the signals to some extent, thus creating the smooth daytime portion of the Red trace. When the Sun sets, the D-layer disappears and the E and F layers take over, the signal becomes stronger, but more unstable and shows as roughness at both ends of the image.

When the transmitter is off, or caught out by unforseen events like the Nepal quake, the trace drops to the bottom of the screen (a bit like an overload). Most navy's of the world use GOES date to avoid such overload's from the sun, but now and then, they are caught off guard from below.

Ha! Ha!, I was trying to make up for the sleep I lost during my failed 24/7 recording transition, I did offer to pay my wife to do the nightshift but she wanted to much (did consider Mother-in law, but I'm not that desperate )

Duffy,