SatNOGS Flowgraphs

SatNOGS GNU Radio flowgraphs.

Installation

Requirements

CMake (> 3.8)
GNU Radio (> 3.8.0)
gr-satnogs

Debian

Dependencies available via openSUSE Open Build Service in the repositories of the home:librespace:satnogs project. When using those repositories, the dependencies can be installed with:

sudo apt-get install build-essential gnuradio-dev gr-satnogs python3-soapysdr

Installation from Source

git clone https://gitlab.com/librespacefoundation/satnogs/satnogs-flowgraphs.git
mkdir build
cd build
cmake ..
make
sudo make install

Usage: The new `flowgraph_dispatcher` tool

Up until satnogs-flowgraphs version 1.5, there have been individual flowgraphs for the multitude of modes, e.g. satnogs_fsk.py or satnogs_fm.py.

In the current master branch and thus with the upcoming release, a single executable flowgraph_dispatcher is provided that will configure the right flow depending on a new command line argument --mode. E.g. replace satnogs_fm.py with flowgraph_dispatcher --mode FM. See flowgraph_dispatcher.py for a complete mapping from flowgraph scripts to modes.

Examples

Before:

satnogs_fm.py \
--soapy-rx-device=driver=rtlsdr \
--samp-rate-rx=2.048e6 \
--rx-freq=435000000 \
--file-path=test.ogg \
--waterfall-file-path=test.dat \
--decoded-data-file-path=test_data \
--gain=40.0 \
--antenna=RX \
--ppm=0 \
--rigctl-host=127.0.0.1 \
--rigctl-port=4532

After:

flowgraph_dispatcher \
--mode FM \
--soapy-rx-device=driver=rtlsdr \
--samp-rate-rx=2.048e6 \
--rx-freq=435000000 \
--file-path=test.ogg \
--waterfall-file-path=test.dat \
--decoded-data-file-path=test_data \
--gain=40.0 \
--antenna=RX \
--ppm=0 \
--rigctl-host=127.0.0.1 \
--rigctl-port=4532

Special case: CW flowgraph and WPM

The CW flowgraph expects the words-per-minute parameter passed with --baud {{WPM}} now. Previously, this parameter was passed with --wpm {{WPM}}.

Before:

satnogs_cw.py \
    --wpm 42 \
    [...]

After:

flowgraph_dispatcher \
    --mode CW \
    --baud 42 \
    [...]

Hard-coded Parameters

The dispatcher starts the flowgraph as well as a zeroMQ subscriber, that writes received telemetry frames into files. For this to function properly, the following values must be passed to the dispatcher:

zmq-dump-host='127.0.0.1'
zmq-dump-port=16887

With a future patch, the dispatch might support alternative values provided by the user, and use those to configure the subscriber accordingly.

Doppler-corrected I/Q streaming via UDP

For realtime analysis during an observation each SatNOGS flowgraph offers streaming of doppler-corrected I/Q data via an UDP sink. The destination of this sink can be configured by the CLI arguments --udp_dump_host and --udp_dump_port. The sample format are 16-bit complex integers, the sample rate varies between the flowgraphs and often depends on the baudrate as well.