I’m waiting on confirmation from the Team, along with (hopefully) a sample file to confirm the characteristics of that 1k2 FSK downlink. But if it’s the same that was in the original AzaadiSAT, then for reference please note in the image below the custom tones (3000:4250) required for Direwolf to decode the signal. (but again, this is from their FIRST satellite - waiting to confirm that we have the same radio for this mission)
Pleased to report on an update from the AzaadiSAT-2 Team regarding the FSK downlink!
With a sample I/Q file, and at their direction, I was able to confirm that the 1200 baud FSK downlink decodes perfectly fine in standard AFSK decoders such as Direwolf and UZ7HO SoundModem as long as the signal is demodulated as USB.
You can also see the DEST & SOURCE callsigns in the decodes below:
That demodulated data clarifies some things! Source callsign is AZDSAT and destination calling is SKITRC - very good! The packet is of message_type == 1, a health beacon packet! Is there a chance we can get a S&F Message packet, too? I didn’t understand if this is only transmitted via LoRa or also via AX.25. I could have a guess on the float sizes, too - let me see!
Scott, could you somehow append the data in ASCII (so I don’t have to copy it from the screenshot ).
float indeed seems to be 4 bytes of size, but endianness is still a question
conversion formulas are missing (how to interpret the obc_temperature e.g.)
I have two bytes leftover that are unparsed at the end (in the screenshot, line 030: positions 2 and 3, values 00 39). Either there is something missing in the struct or there’s a size that doesn’t match
transmitted_on is the indicator on which transmitter the data has been transmitted?
We are yet to setup our SatNOGS station yet so not able to schedule observations, can someone help with creating observations over potential passes of the ground station? TLE is already given in the previous message.