# Gr-ais not decoding AIS data **URL:** \ **Category:** GNU Radio\ **Created:** [August 27, 2014, 12:37am UTC](https://www.ruby-forum.com/t/gr-ais-not-decoding-ais-data/231733 "2014-08-27T00:37:28Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [August 27, 2014, 12:37am UTC](https://www.ruby-forum.com/t/gr-ais-not-decoding-ais-data/231733/1 "2014-08-27T00:37:28Z")
Hi, I’ve just started poking around with gr-ais on a new Ubuntu 14.04 install. I grabbed it from [GitHub - bistromath/gr-ais: Automatic Information System decoder for shipborne position reporting for the Gnuradio project](https://github.com/bistromath/gr-ais.git) and it compiled fine, but when I feed it “ais.dat” from [http://www.nerdnetworks.org/~bistromath/ais.dat.tar.gz](http://www.nerdnetworks.org/~bistromath/ais.dat.tar.gz) it doesn’t output any AIS data:  :~$ ais\_rx -s Downloads/ais.dat -r 256e3 -g 60 Using file source Downloads/ais.dat Rate is 256000 Using Volk machine: sse4\_2\_64\_orc :~$ The data file looks good as the FFT and Waterfall plots in GRC clearly show the recorded AIS data. Is this an issue with the transition to gnuradio 3.7? Cheers, Josh ---
**Author:** ![Josh\_Hattery](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ebca7d/32.png) [@Josh\_Hattery](https://www.ruby-forum.com/u/Josh_Hattery)\ **Post date:** [August 27, 2014, 12:50am UTC](https://www.ruby-forum.com/t/gr-ais-not-decoding-ais-data/231733/2 "2014-08-27T00:50:15Z")
Strange. You have the correct settings. I’ll look into that now. I’ve been operating gr-ais from a separate branch lately (the “msk” branch), but it depends on some blocks which I haven’t gotten permission to contribute back upstream yet. Hopefully by GRCon I’ll have permission and can move them into master; the MSK sync blocks help a lot with AIS performance. –n