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muccc / iridium-toolkit

A set of tools to parse Iridium frames
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ERR:Message: Can't parse problem! #120

Open Rango-T10000 opened 2 weeks ago

Rango-T10000 commented 2 weeks ago

I use a IAA.01.121111 Iridium Certified Antenna connected to a LNA and USRP X310 to receive the iridium Signal via gr-iridium.

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When I run the gr-iridium, the terminal ouput shows like this:

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And I can get the ouput.bits file, then I use iridium_parser.py to parse this file: "pypy3 iridium-parser.py ./output.bits > output.parsed", however, the parse is totally failed! The oupur.parsed like this:

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According to , I try "--uw-ec" and "--errorfree" command, but still can not work. Could you please tell me what is the problem in my whole precess? Any advice? Really thanks.

Sec42 commented 2 weeks ago

Your i/s numbers are often in the hundreds, which means gr-iridium detects some energy, but your ok numbers are very low (they should be at least 30% if not higher), which means that most of these are not valid iridium packets.

Furthermore, the ones that you tried to parse are all untypically short - I would expect a lot more longer packets.

From that I conclude that your reception is pretty bad.

It suspect like you have a lot of interference. I suggest looking at the spectrum at 1.626GHz in gr-fosphor or a similar waterfall to verify the spectrum is clean.

In general I would suggest to move both the USRP and the antenna as far away as cables permit from the rest of your equipment (i.e. laptop and power supply) and use a good shielded USB cable to connect the USRP to the laptop.

donbmouse commented 1 day ago

Hello, I have used a HackRF setup of this toolkit as a control for over a year. But in the past couple of months, I have been seeing the same problem as Rango, above. Nothing in my rx chain has changed and the sky/location is the same. Is it possible the Iridium protocol has changed slightly? Or are you seeing packet consistency in other areas? I am in northern USA. Thanks

donbmouse commented 1 day ago

Actually in case this helps anyone else that has suddenly had the same issue over the past month or so, a change in a local network provider (possibly others?) has increased saturation in this band. gr-fosphor helped identify it and I was able to reduce the interference enough to get packets back. Thanks for the recommendation to use it, as I did not expect the problem to suddenly be this level of interference.