Howto receive and decode NOAA APT images with the Funcube Dongle and Gqrx

NOAA-18 APT receptionOne of the great advantages of software defined radio receivers is that tuning receiver settings is a matter of adjusting software parameters. Gqrx is no different here and has optimal settings built in for weather satellite reception. This tutorial describes how to receive automatic picture transmissions (APT) from NOAA weather satellites using Gqrx SDR, record them to a WAV file, and finally decode the images using the free and open source Atpdec decoder. If you follow this guide you can end up with very nice results such as the one shown at the end.

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Gqrx on Mac OS X (almost)

Few weeks ago, or maybe a month or two – I don’t remember, I spent an afternoon trying to build gnuradio-core and gr-audio on Mac OS X without using any macports. It was a casual an undocumented attempt that resulted in a compilation failure. I wasn’t surprised because I made several mistakes along the way, so I just left it an moved on.

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Gqrx SDR receiver


Please visit the new Gqrx website. The information on this page is no longer updated!


Gqrx is a software defined radio receiver for Funcube Dongle (FCD), RTL2832U-based DVB-T devices (RTL-SDR), Universal Software Radio Peripherals (USRP) and Osmo SDR devices. It is powered by GNU Radio and the Qt GUI toolkit.

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Qtmm soundcard modem for decoding AFSK1200

Last week I started on a new experiment trying to integrate the AFSK1200 demodulator code from multimon into a simple Qt-based graphical application. This experiment had two objectives:

  1. Test the feasibility of integrating the AFSK1200 demodulator from multimon into other applications.
  2. Try using the QAudio framework from Qt for audio I/O that should work on both Linux, Windows and Mac OS X.

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First on the air tests of gqrx

With both the frequency controller and FFT plot widgets in place gqrx was ready for the first on the air tests. The video below shows the first reception of the AO-27 amateur radio satellite during orbit 92436 and 92437, using the Funcube Dongle receiver that I use for portable space communication.

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