fm_demod script that also writes waterfall data (credit to surligas, I'm just committing)
Also FFT needs to be added to CMakeLists.txt to build in some conditions.
see also satnogs/gr-satnogs#42
Taking out WBFM/NBFM for a straight quadrature demod method
Change from 44.1k output to 44k output to be more compatible
with gr-satellites
Also changing rtlsdr to a 2msps rate by default
* UDP Message source can handle multiple data types
* Add a waterfall sink block
* Fix dependency issues with VOLK
* Add mean and max hold mode to the waterfall sink
* Add mean and max hold mode to the waterfall sink
* Install satnogs_waterfall.gp gnuplot script at
<install_prefix>/share/satnogs/scripts
* Automatically retrieve x and y axis ranges at the satnogs_waterfall.gp
The FM demodulator now supports a variaty of hardware setups and saves
the WAV file for further processing. A set of command line arguments can
control most of the flowgraph internals, such as the wav file name and
storage path e.t.c.
TODO: Check the settings for all the available hardware
The new transceiver has an FSK9600 receiver that supports legacy G3RUH
scrambled AX.25 frames.
However, due to some restrictions the transmitter is a custom structured
9600 FSK with a preamble of 8 bytes and 2-byte sync word.
The FM demodulation flowgraph uses the high performance Xlating FIR
filter for filtering and frequency centering at the same time. Tuning
the SDR in a frequency different than the frequency of interest, we
avoid the DC offset that the of the SDR. As far the audio sampling rate
concerns, various configurations are supported due to the Polyphase
Filter-bank arbitrary resampler.
The flowgraph supports also doppler compensation based on RIGCTL
commands. Instead of chaning the SDR frequency, we digitally perform the
proper correction to avoid noise and lost samples during the frequency
re-configuration. The doppler correction mechanism gathers the frequency
changes from the RIGCTL daemon, and predicts the frequency changes
between the RIGCTL messages for better and more fine-grained correction.
Pierros Papadeas
Alfredos-Panagiotis Damkalis
Corey Shields
Manolis Surligas
Manolis Surligas
Fabian P. Schmidt