So the control channels are the narrow ones? I’m guessing the really wide ones
are the traffic. (On a side note, I’m kind of surprised that people [you and
killmore231] can get Inmarsat with a patch. I just barely see the signals with
9A4QAV’s helix and an SDRplay. However, Iridium comes in like a blowtorch.)
Anyway, can’t wait to see your program. Is it on Github?
Sent from Windows Mail
From: Kevin McQuiggin
Sent: Tuesday, May 3, 2016 10:02 PM
To: Henry Barton
Cc: [email protected]
Hi Henry:
I have an Inmarsat demodulator working for the lower speed control channels. I
am writing a program to decode the traffic, but this is not a trivial task.
Think on the order of 1000 lines of C. It is "almost" working, I am hoping for
valid output in the next week or so, depending on my free time.
My program is currently a standalone program, but once it's done it could
conceivably be converted to one or more gnuradio blocks.
I suggest the following document to give you background on the channel
specifications for Inmarsat:
http://www.icao.int/safety/acp/inactive%20working%20groups%20library/acp-wg-m-iridium-8/ird-swg08-wp07%20-%20old_amss_material_ch.4_plus_attachment.doc
The demodulation is fairly easy, read the spec document and the channel
characteristics are pretty well described. My gnuradio demodulator is based on
the GMSK demod block. I'm using a home brew patch antenna, and the LNA4ALL low
noise amplifier.
Kevin
Sent from my iPad
On May 3, 2016, at 12:45 PM, Henry Barton <[email protected]> wrote:
http://rtlsdrblog.rtlsdrblog.netdna-cdn.com/wp-content/uploads/2015/10/sdrplay_lband-1024x573.png
I didn’t see the widest signal (bright yellow) from this picture on
sigidwiki.com. Does anyone know what it is? If so, can it be decoded by
GNUradio? Thanks.
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
