[time-nuts] Fwd: [hpsdr] SDR experiment for the solar eclipse

Alan Melia alan.melia at btinternet.com
Thu Aug 3 15:57:29 EDT 2017

A Time Nut would measure phase change across the path of totality using GPS 
locked SDR receivers :-)) As was done on the Eclipse that passed between the 
UK and Iceland a couple of years ago. Keflavik NRK's ionospheric signal was 
returned from inside the path of totality to most of the north of the UK, 
giving a good measure of the change in height of the "apparent reflection 
height" in the D-layer.

The quoted program looks a bit scattergun......lets record everthing and see 
what's there.
Hopefully it will involve a lot of school kids and maybe interest them in 
science and electronics. If it does that it will be more useful that we 
could imagine.


----- Original Message ----- 
From: "John Ackermann N8UR" <jra at febo.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, August 03, 2017 8:10 PM
Subject: [time-nuts] Fwd: [hpsdr] SDR experiment for the solar eclipse

> This is a little off-topic, but thought some of the group might be 
> interested... so please forgive the interruption.
> John
> -------- Forwarded Message --------
> Subject: [hpsdr] SDR experiment for the solar eclipse
> Date: Thu, 3 Aug 2017 15:07:57 -0400
> From: John Ackermann N8UR <jra at febo.com>
> To: FMT-nuts at yahoogroups.com, HPSDR list <hpsdr at lists.openhpsdr.org>
> ***** High Performance Software Defined Radio Discussion List *****
> I've been working with the "HamSci" group to set up an experiment for the 
> solar eclipse: wideband recording of several HF bands before, during, and 
> after the eclipse to look for propagation changes (or anything else that 
> happens).  All are welcome to participate in the experiment, and this is a 
> *perfect* application for our SDRs!
> Here's the HamSci web page:
> http://hamsci.org/2017-eclipse-hf-wideband-recording-experiment
> Various SDRs and programs have wideband recording capability.
> Radios that support the HPSDR "old protocol" (which include Hermes-based 
> boards as well as the Red Pitaya and possibly others) can do an even 
> better trick: they can record multiple slices of the HF band 
> simultaneously, thanks to work by Tom McDermott N5EG.
> Hermes can do 4 receivers (tested), Mercury/Metis/Atlas systems should 
> handle 3 (not tested), and the Red Pitaya can support 6 (tested).  This 
> means that we can record most of the 80M band, and all of 40, 30, and 20M, 
> in one gulp to look for effects of the eclipse -- frequency shift, 
> propagation enhancement/reduction, noise floor, etc.
> I've written a Gnuradio .grc program that used N5EG's driver to record 
> multiple receivers.  By default it's configured for four receivers on 
> 80/40/30/20M, but that's easy to change.  I'll be posting that software to 
> the TAPR github at https://github.com/TAPR as soon as we've done a bit 
> more testing.
> This software runs on Linux and may work on Windows (I haven't had a 
> chance to try, but Gnuradio has been ported to Windows).  Recording 4 
> 384kHz channels does take some computing horsepower and uses a lot of disk 
> space -- about 3MB per receiver per second.  My prior-generation i7 
> machine with solid state drive seems to handle it OK.
> If you're interested in participating in this experiment, please (a) check 
> out the HamSci web page; (b) check the ttps://github.com/TAPR in a day or 
> two to grab the software and docs; and (c) feel free to contact me 
> directly with any questions.
> 73,
> John N8UR
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