gr-ais with osmosdr
chris at techworks.ie
Sun Aug 5 18:45:28 UTC 2012
I saw a message in the July archive (I wasn't subscribed yet at that
date) about updating gr-ais with osmosdr support.
I was working on the same thing recently, so i decided to publish my
fixes on top of Antoine's one.
The result can be found here:
I got it working with both an FCD and an RTL:
ais_rx.py --rate 96e3 --gain 30 --error -17 -d -D fcd=0
ais_rx.py --rate 1024e3 --gain 30 --error -110 -d -D rtl=0
Strangely passing freq_err=XX parameter to the source (using -D),
doesn't work, the use of --error is thus needed (which will do a
Antoine, if you want sample file, just let me know.
Nick, are you willing to integrate these changing back in gr-ais, Apart
from the added automatic decimation filter, the changes are not
intrusive at all.
The default settings for UHD are 256Khz sampling with decimation filter
4, with this change, the decimation is one when using FCD (96KHz fixed
frequency) and 16 for RTL when used at 1.024MHz (this was the minimum
working frequency for me).
Or maybe would you prefer to allow the user to set it manually, and use
this technique as a fall back only.
Please let me know what you guys think.
Embedded systems engineer.
1 Harbour road
Tel: + 353 (0) 1 236 5990
More information about the osmocom-sdr