goestools
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pietern
Add support for HackRf.
I have have verified that I am able to collect images with a HackRf plus a GOES SAW Bird (LNA + SAW Filter) attached to my laptop.
Hi, thanks Pietern for the tools and Nqbit for this PR!
I'm currently testing this but I get false locks at most frequencies (It locks on at 10MHz, 100MHz and the actual LRIT frequency, but not at 1MHz). It immediately locks, then gives me a string of ones. Viterbi error is 16 every single time at LRIT frequeny. Frequency offset jumps around between -20 and 20Hz. Goesrecv-monitor output can be seen here:
My setup works fine with this fork using an RTL-SDR. The Hackrf also seems to work fine in other situations (eg I can receive FM using GQRX). I don't know the specifics of the dish/LNA as I've just been provided with a line, but can find out if that's relevant.
My hackrf_info gives the following: hackrf_info version: unknown libhackrf version: unknown (0.5) Found HackRF Index: 0 Serial number: 0000000000000000088869dc382d851b Board ID Number: 2 (HackRF One) Firmware Version: 2021.03.1 (API:1.04) Part ID Number: 0xa000cb3c 0x0066475e
The same issue was present with older firmware (2018.something). I'm using Ubuntu 20.04. I would really love to get this working and would really appreciate any help. I'm also very happy to help test this PR. -Sam
@kazaril Hey Sam, are you sure you're pointing at the right satellite? It is possible you're looking at GOES-18 which is only transmitting a HRIT carrier at this point. That is consistent with the constellation you're seeing.
@pietern the signal is immediately locking regardless of what frequency I select. I can receive LRIT fine using the RTLSDR dongle with the same setup, but I'm wanting to get the HackRF working so that I can move on to HRIT (pretty sure the RTLSDR doesn't have the bandwidth for it)
EDIT: OK, so it looks like the issue is due to HackRF having a big spike at centre frequency due to not having matched components (they had to make some sacrifices to keep the price down). I might have to write something to filter it/have a frequency offset. I wonder why @nqbit didn't have this issue, maybe just got lucky with his HRF.
@kazaril I am now having the exact same issue as you with the large DC spike in the center causing lots of issues. Were you able to get a frequency offset working? I have a frequency offset working fine in GQRX but I'm not sure how I would implement something similar into goestools. I'll take a stab at it unless you already have something working.. Thanks
@gornstein I fumbled around for a while trying to add the offset to the code but in the end just switched to Satdump as it has a DC block option built in. If you do end up getting the offset working in Goestools please let me know - I'd be very curious to hear how it performs.
@kazaril alright thanks, I'll be sure to let you know if I get anything working!