Many thanks for the info.
Will try it!
----- Original Message -----
From: Marcus D. Leech
To: [email protected]
Sent: Sunday, September 25, 2011 17:04
Subject: Re: [Discuss-gnuradio] X-Ray flare observations with GnuRadio
On 25/09/11 08:29 AM, Patrik T. wrote:
Tell us more how you did it.
- antenna used?
Many SDR users in Northern Scandinavia are up day and night
listening on submarine traffic on VLF.
I use a square-loop antenna, roughly 1.5M in diameter. I have roughly
80M of 22ga wire wound onto it.
This feeds a Behringer Mini-Mic 800 microphone preamplifier, which
is then fed into a 96KHz sound
card–no USRP required.
The software I wrote for this I call SIDsuite. It’s available via
It works by measuring the received signal stength for various VLF
transmitters–most of them are indeed
submarine communications systems. The signal strength follows a
diurnal pattern involving solar
radiation and the D and E layers of the ionosphere. When there are
strong solar X-ray events, that
pattern is disturbed–sometimes spectacularly.
Shirleys Bay Radio Astronomy Consortium