Tuesday, 11 October 2011

GNU Ionospheric Tomography Receiver (Jitter)

I am releasing the ionospheric tomography receiver that I have been
working on for a couple of years. The receiver is not related to the
GNU Digital Beacon Receiver provided by Prof. Mamoru Yamamoto, which
can be used for a similar purpose. The receiver looks at Russian
Tsykada, US Radcal, and DMPSF15 satellites that transmit 150 and 400
MHz beacon signals. The FORMOSAT satellites should also be usable,
although they do not seem to transmit anything above Northern
Scandinavia, so I haven't been able to test them. From these signals,
it is possible to derive the relative propagation delay between 150
and 400 MHz (other frequencies can also be used with the receiver).
The propagation delay is approximately related with the line integral
of the ionospheric electron density between the satellite and the
receiver. With a large enough network of receivers, it is possible to
perform limited angle tomography of the ionospheric electron density,
which is what my group is planning to do with this receiver.

The receiver package that I am now releasing is intended for use with
such a large scale tomography receiver chain. The receiver is capable
of autonomous operation and it can observe multiple beacon satellites
simultaneously. The receiver is written with C++ and the relative
propagation delay calculation is performed using GNU R. A normal PC
will be able to perform all of these calculations, although you will
need about 4 GB of memory for the phase curve calculation part.

I am not releasing any tomographic reconstruction software yet, but
this might happen in the future.

Here is the web site for my receiver, which I am choosing to call
Jitter (GNU Ionospheric Tomography Receiver):

http://www.sgo.fi/~j/jitter/web/

The software is still in alpha stage, but it has been used with
several test receivers for several months of continuous operation. I
have used it successfully with usrp1 and two WBX daughterboards, but
also recently I have managed to get USRPN210 and TVRX2 working. The
receiver can be locked to a GPS reference, but this is not necessary.
If you are interested using my receiver, feel free to contact me.

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