Does anyone have an SDR recording of CAS4A / CAS4B? I would like to try to demodulate and decode the 4800 baud telemetry signals and see what they say.
Regards, Douglas
Hi Douglas, all,
On the next passes over the south of western Europe, tomorrow morning, I will record an i/q file and give you a link to download it (caution : 1 mn ==> 100 MB).
Despite the fact that the two birds here never climbs very high above the horizon, maybe 30 deg., the signal is very strong and the demodulation of the 4800 bps GMSK telemetry very easy. During the pass, you doesn't lose a frame. Conditions : GPA + preamplifier in the attic, FCD-Pro+, Gqrx (SDR prgm), Gpredict (Doppler shift tracking), DireWolf 1200/2400/4800/9600 bps FSK/GMSK demodulator).
Have a nice evening, 73 !
J-P F5YG
On 16/06/2017 16:30, Douglas Quagliana wrote:
Does anyone have an SDR recording of CAS4A / CAS4B? I would like to try to demodulate and decode the 4800 baud telemetry signals and see what they say.
Regards, Douglas _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Douglas, if this can help, you will find here : http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_telemetry.txt 152 frames of the pass, orbit nr 17, this morning June 16th, starting at 0730 UTC, each frame 147 bytes (coded hexa).
73 !
J-P F5YG
On 16/06/2017 18:31, Jean-Pierre Godet wrote:
Hi Douglas, all,
On the next passes over the south of western Europe, tomorrow morning, I will record an i/q file and give you a link to download it (caution : 1 mn ==> 100 MB).
Despite the fact that the two birds here never climbs very high above the horizon, maybe 30 deg., the signal is very strong and the demodulation of the 4800 bps GMSK telemetry very easy. During the pass, you doesn't lose a frame. Conditions : GPA + preamplifier in the attic, FCD-Pro+, Gqrx (SDR prgm), Gpredict (Doppler shift tracking), DireWolf 1200/2400/4800/9600 bps FSK/GMSK demodulator).
Have a nice evening, 73 !
J-P F5YG
On 16/06/2017 16:30, Douglas Quagliana wrote:
Does anyone have an SDR recording of CAS4A / CAS4B? I would like to try to demodulate and decode the 4800 baud telemetry signals and see what they say.
Regards, Douglas _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi Douglas, all!
I'm late as Scott just shared his full pass excellent i/q file and nice video. If this can help, I recorded only 50 secondes of the last pass over western Europe (orbit nr 32) so that the files don't become too large.
A 32-bit floating point raw i/q file (for Gqrx, etc...): http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_20170617_orb32.raw
The same one translated in a PCM 16-bit wav file (for SDR#, etc...): http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_20170617_orb32.wav
The full 199 frames of this 50 seconds record (text hexa): http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_20170617_orb32.txt
And the sound of space with the CW telemetry (mp3): http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_20170617_orb32.mp3
Have a nice w.-e.!
J-P F5YG
On 16/06/2017 19:03, Jean-Pierre Godet wrote:
Douglas, if this can help, you will find here : http://f5yg.pagesperso-orange.fr/incoming/CAS-4A_telemetry.txt 152 frames of the pass, orbit nr 17, this morning June 16th, starting at 0730 UTC, each frame 147 bytes (coded hexa).
73 !
J-P F5YG
On 16/06/2017 18:31, Jean-Pierre Godet wrote:
Hi Douglas, all,
On the next passes over the south of western Europe, tomorrow morning, I will record an i/q file and give you a link to download it (caution : 1 mn ==> 100 MB).
Despite the fact that the two birds here never climbs very high above the horizon, maybe 30 deg., the signal is very strong and the demodulation of the 4800 bps GMSK telemetry very easy. During the pass, you doesn't lose a frame. Conditions : GPA + preamplifier in the attic, FCD-Pro+, Gqrx (SDR prgm), Gpredict (Doppler shift tracking), DireWolf 1200/2400/4800/9600 bps FSK/GMSK demodulator).
Have a nice evening, 73 !
J-P F5YG
On 16/06/2017 16:30, Douglas Quagliana wrote:
Does anyone have an SDR recording of CAS4A / CAS4B? I would like to try to demodulate and decode the 4800 baud telemetry signals and see what they say.
Regards, Douglas _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sorry it took me so long to zip & upload the IQ recording from Friday morning U.S. time, Douglas.
If anyone has not had a pass from the new CAS-4A or 4B satellites yet, feel free to download a PCM-16 IQ wav file of the pass from:
http://www.qsl.net/k/k4kdr//files/HDSDR_20170616_103700Z_145735kHz_RF--cas4a...
... for anyone not completely familiar with SDR's yet, this is not an audio .wav file, but an "IQ" wav file suitable for replaying in SDR software. Comes in very handy for testing decoders or sharing like this between people so we can benefit from others' big antennas, geographical location, or lack of sleep!
I certainly hope the voice transponder has a signal as strong as these 4k8 telemetry streams. This file was recorded unattended using a 2m X-Quad (no pre-amp) to an SDRPlay SDR. However, after seeing the signal on the screen, you might be able to receive it with a coat hanger.
Instead of downloading my recording and playing it back yourself, if anyone would just like to see the signal and volume of data being downloaded, I put up a short video at:
https://www.youtube.com/watch?v=Yzvi9oWcxhQ&feature=youtu.be
73!
-Scott, K4KDR
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-----Original Message----- From: Douglas Quagliana Sent: Friday, June 16, 2017 12:30 PM To: amsat-bb@amsat.org Subject: [amsat-bb] CAS4A CAS4B SDR recordings?
Does anyone have an SDR recording of CAS4A / CAS4B? I would like to try to demodulate and decode the 4800 baud telemetry signals and see what they say.
Regards, Douglas
participants (3)
-
Douglas Quagliana -
Jean-Pierre Godet -
Scott