Hi,
I have set up a client (id: 233) and I could successfully schedule some NOAA satellite observations.
After resampling the audio files using sox I can decode the images using wxtoimg.
How can I do this using satnogs software? And how is it possible to upload the results so I can see the image in the “data” section of an observation?
I have also installed satnogs-gr. I could not find any documentation or forum thread providing a solution.
Well the client will attempt to automatically decode the APT image. I am not sure about how you would upload it.
(I am saying this from experience with my own station #95)
OK. Thanks for your answer.
Now it seems like my client stopped also uploading the audio and waterfall.
I checked the log files and found this:
Mar 06 11:41:49 raspberrypi satnogs-client[572]: Exception in thread Thread-6759:
Mar 06 11:41:49 raspberrypi satnogs-client[572]: Traceback (most recent call last):
Mar 06 11:41:49 raspberrypi satnogs-client[572]: File “/usr/lib/python2.7/threading.py”, line 801, in __bootstrap_inner
Mar 06 11:41:49 raspberrypi satnogs-client[572]: self.run()
Mar 06 11:41:49 raspberrypi satnogs-client[572]: File “/usr/lib/python2.7/threading.py”, line 754, in run
Mar 06 11:41:49 raspberrypi satnogs-client[572]: self.__target(*self.__args, **self.__kwargs)
Mar 06 11:41:49 raspberrypi satnogs-client[572]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 127, in _communicate_tracking_info
Mar 06 11:41:49 raspberrypi satnogs-client[572]: self.check_observation_end_reached()
Mar 06 11:41:49 raspberrypi satnogs-client[572]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 175, in check_observation_end_reached
Mar 06 11:41:49 raspberrypi satnogs-client[572]: self.trackstop()
Mar 06 11:41:49 raspberrypi satnogs-client[572]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 168, in trackstop
Mar 06 11:41:49 raspberrypi satnogs-client[572]: os.killpg(os.getpgid(self._gnu_proc.pid), signal.SIGKILL)
Mar 06 11:41:49 raspberrypi satnogs-client[572]: OSError: [Errno 3] No such process
Anybody who can help?
Maybe I will start all over again and rewrite the image to the SD card 
Even after reinstalling everything I still can’t see any demoded data.
Has anyone a hint for me which log file I should check?
Or can someone explain me how demodulation can be done manually using the script satnogs_noaa_apt_decoder.py ?
Hey @MasterJ sorry to hear you are having troubles.
Can you share a bit your setup details? SDR? Operating system? How did you do the installation?
Thanks!
Hi @pierros Thanks for trying to help me!
I have a RPI3 and an rtlsdr dongle and a QFH antenna. So far I don’t have a LNA.
I am using the provided Raspbian image.
I ran satnogs setup and updated the tool.
Then I entered the API key and so on.
I followed these instructions: https://wiki.satnogs.org/Raspberry_Pi_3
Scheduling observation works and the audio and waterfall is uploaded.
(https://network-dev.satnogs.org/observations/?station=233)
But the demodulation fails.
I checked the log messages
journalctl -f -u satnogs-client.service
I could only find a message like “no dimension information”.
Sadly the log file was cleared in the meantime.
Is there a way to run satnogs_noaa_apt_decoder.py manually?
Hey @MasterJ,
I have reviewed the uploaded Waterfalls and I think your problem is the really low SNR due to bad signal reception.
Have you measured the antenna? What line do you use? Gain settings? LNA? filter?
Hi @pierros
So far I have neither a LNA nor any filter.
I haven’t measured my antenna. Actually I am a beginner in amateur radio and sdr.
I am wondering because I am able to decode the downloaded and to .wav converted .ogg files with wxtoimg. The images are not the best but I have seen images uploaded in the ‘data’ section of other observations that were not better. Before i set up my client I recorded the audio using gqrx with a bandwith of around 50kHz sometimes I got quite good images when the satellite passed nearby.
What I am searching for is an error message, that tells me what went wrong. But I can’t find any.
My latest try was to use my ground station in standalone mode to understand how it works. But obviously I ran into a new problem. I searched the log file and I found this:
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: Exception in thread Thread-2550:
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: Traceback (most recent call last):
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: File “/usr/lib/python2.7/threading.py”, line 801, in __bootstrap_inner
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: self.run()
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: File “/usr/lib/python2.7/threading.py”, line 754, in run
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: self.__target(*self.__args, **self.__kwargs)
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 127, in _communicate_tracking_info
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: self.check_observation_end_reached()
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 175, in check_observation_end_reached
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: self.trackstop()
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: File “/var/lib/satnogs/local/lib/python2.7/site-packages/satnogsclient/observer/worker.py”, line 168, in trackstop
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: os.killpg(os.getpgid(self._gnu_proc.pid), signal.SIGKILL)
Mar 19 11:25:47 raspberrypi satnogs-client[1392]: OSError: [Errno 3] No such process
Thanks again for your help!
Just for others who might stumble upon the same problem:
I found this topic:
I changed the default value of the --sync option in the satnogs_noaa_apt_decoder.py to sync=0. This made my client successfully decode and upload images.
But then I found out that even with sync=1 my client could successfully decode images and upload them:
I adjusted the ppm error as described here: Adjusting the SatNOGS Client - SatNOGS Wiki
Furthermore I also adjusted the three gain values through satnogs-setup.
I played around with gqrx and in the end I used the highest value 49.5 [dB].
Now it seems like at least sometimes NOAA 19 images are decoded successfully.
setup: cheap RTL2832U device + RPI3 + satnogs-image + selfmade QFH antenna