Regarding Observation 11433963 …
Any decoder for the ArcticSat-1 ?
Hello,
There is no decoder on SatNOGS side at this moment, but in addition to SatNOGS -client/-flowgraph, some station owners install gr-sat and “link” it to the SatNOGS client to be able to decode ArcticSat-1 (and other sats that doesn’t have decoder on SatNOGS side). Here is the example of ArcticSat-1 on my station : https://network.satnogs.org/observations/?norad=61762&start=&end=&observer=&station=3106&results=d1&transmitter_mode=)
Here are some instructions on how to do it (at least for a classic SatNOGS client installation, there are some active dev right now and versions with some changes,i don’t know which kind of installation you performed).
This integration will currently not work with the new SatNOGS docker solution.
See the missing features wiki page.
Yes, my point exactly when i said “at least for a classic SatNOGS client installation, there are some active dev right now and versions with some changes”, thanks for being more precise ^^ i m a bit lost in all those updates i see passing by on client.
For my knowledge is there some how any even approximatively view on when these missings feature will be addressed ? Personnaly i won’t update mine until at least the possibility to add gr-sat 
and for my new one, i will need the rotator support so same thing. Anyway sorry this out of topic question here
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After demodulation via gr-satellites - Sputnix.ksy might work as a decoder for ArcticSat-1 packets
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Thanks! that is definitively something that can be tested Going to have a look at it.
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Please let us know!
Related question since I want to try as well: I see that gr-satellites is only for Linux. someone tried to used on wsl on windows? does it work?
Yes, gr-satellites will also work when using WSL.
I have used the build from source option Installing from source — gr-satellites 5.8.0-git documentation on a debian and ubuntu distro.
There won’t be a real time decode when running gr-satellites on another system then your satnogs-client.
Jan | PE0SAT
I tried to decode your obs, but it seems there isn’t enough SNR
If you want to test a obs with enough SNR, have a look at SatNOGS Network - Observation 11444828 I can also share the IQ recording if you want to.
Here an offline, replay of that obs using the IQ recording
gr_satellites 61762 --rawint16 iq_1696_11444828_48000.wav --samp_rate 48e3 --iq
-> Packet from 2k4 USP FSK downlink
Container:
header = Container:
addresses = ListContainer:
Container:
callsign = u'R2ANF' (total 5)
ssid = Container:
ch = False
ssid = 0
extension = False
Container:
callsign = u'RS74S' (total 5)
ssid = Container:
ch = False
ssid = 1
extension = True
control = 0x00
pid = 0xF0
info = b'FB\x02\x00\x01\x00\x19\x00\n\x00\xffr"\x08\xc1\x0em\xa0\x04h\x8a\x0c\x00\x00`\t\x00\x00&\x00 \x1f\x00!\xed\x04\x00\x01\x000\x00i\x13\x15\x14\xf8\x13\x00\x00\x00\x00\xa6\x00+\x00\x00\x000\x00\x00\x00\x00\x00\x00\x00\xc8\x00,\x01\xfa\x00\x13\x01\x00@\x00\x000\x1f\x8f\x0c\x00\x00\xb3\t\x95ZQ\x04' (total 89)
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I guess my antenna is not the best in terms of SNR… or at least this is what it seems from my observations… maybe I can change something in the configuration… not really sure what however
The observation mode was SSTV, which is optimized for a much wider deviation, this results in a not optimal demodulation and harder to get any frames from the audio.
Jan’s obs is running 9k6 but the actual mode is 2k4, this is not optimal either, but the resulting audio is able to recover most frames from.
The live demod runs from the raw IQ-data and gr-satellites chooses the deviation for each of it’s supported modes simultaneously. The satyaml also has the deviation set, so will be pretty good at this.
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Can you share some details on your dipole antenna, to be honest I am pretty surprise by the amount of frames it is picking up.
The easiest way get some extra SNR is to add a LNA, I have pretty good results with the Nooelec wide band models, far from optimal but a start.
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Sure!
This is the exact setup:
- Antenna - Dipole + RTL-SDR bought from here
- connected through usb3.0 to rasperry pi4
- and I run the docker installer from Satnog, using step by step guid (btw… super fantastic and easy!)
- the two arms of the antenna should be around the 120deg spam between the two. (cannot be precise 100%)
- Location: I’m still trying to get access to the upper roof but at the moment is attached to my balcony and I have full FOV between North-West-South (yes I know is not optimal but I need to find a better location)
I know it’s a very cheap and rudimentary setup, but I just started and I didnt expect to get actually data…
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Its not a simple V dipole… the balcony railing its a reflector.
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Yes, so for my next location I’ll definitely consider to stay far from metal sources. this might already improve. noted.
well, it’s not always bad, it can provide directionality, if you want it (: althou a traditional reflector for a yagi (even 2el) is a very specific length.
it also affects impedance, which the angle of the V also does. so if the design calls for 120deg in free space, it will probably go a bit lower if it is close to a balcony rail for example.
for reception I would not worry too much about it, where the main lobes point and what signals you get is more important than perfect matching.
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Hello,
So i had a look, but the decoder “sputnixusp.ksy” (no sputnix.ksy one found) unfortunatelly doesn’t work. Well it works because it is AX25 so we have the header, but the payload (no 0x4216: general_tlm or 0x4217: extended_tlm types) is not decoded (so it doesn’t do much more work than ax25monitor.ksy).
(exemple)
{
"callsign": "R2ANF ",
"ssid_mask": 96,
"ssid": 0,
"src_callsign_raw_callsign": "RS74S ",
"src_ssid_raw_ssid_mask": 99,
"src_ssid_raw_ssid": 1,
"ctl": 0,
"pid": 240,
"packet_type": 16966
}
That said, if you have documentation about the format of ArcticSat-1, i would be happy to do a decoder for it and provide a dashboard
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There is Sputnix Telemetry Viewer. If you go to main catalogue → resources → devices-en → aUHF_msgid.xml. If you’ll open it with text editor you could see msg ids and packet fields which may be parsed.
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Found this ARCTICSAT-1 | R4UAB
Not sure that can help to decode tough.
You need to use the google translation 