Connecting the waterfall sink behind the FFT Filter causes the
waterfall to show only the filtered APT signal. Fixing this needs
an additional resampler.
The flowgraph for decoding NOAA APT images generates a waterfall with a
bandwidth depending on the default samplerate of the SDR hardware.
USRPB200 defaults to 500 ksps, which produces an output of 125 ksps
after the "first_stage_decimation" which is fixed to a value of 4.
Changing the hardware to an "rtlsdr" also changes the default
samplerate to 1 Msps which results in a waterfall bandwidth of 250 kHz
(+- 125 kHz). Connecting the waterfall sink behind the FFT Filter,
which has a decimation set to match an output samplerate of 125 kHz,
seems to be correct! This produces waterfalls with a bandwidth of
125 kHz (+- 62,5 kHz).
Fixes issue #128
* Set all decoders output to binary format
* Introduce the quadrature demodulation filter in all affected
flowgraphs, in order to reduce false alarms and increase performance
The CMake build system will first try to locate libfec in the system. if
it is not available, it will start building the libfec that is part of
the gr-satnogs source code. During the installation libfec is installed
in the system, thus future builds will make use of it and will not
rebuild from source.
* Set the METEOR flowgraph in non-X mode
* Reduce the stored bandwidth by a factor of 2. Captures have shown that
twice the bandwidth of the METEOR is enough for RRC and clock recovery
This commit adds a inital METEOR flowgraph that can be used for
capturing raw IQ. The capturing is performed in a sampling rate of
320KSPS which is more than enough for actual decoding for both METEOR
modes (72K and 80K). Due to icnreased bandwidth no audio file is
generated.
All flowgraphs now support user defined parameters for most of their
configuration capabilities. These include:
* RF gain
* IF gain
* BB gain
* Custom device arguments for setups with multiple SDRs. These
coresponds to the 'Device arguments' field of the Osmocom source block.
* Antenna selection for devices with multiple antennas (USRPs, etc)
Changing sampling rate is not supported (yet).
For listing the arguments just execute <flowgraph> --help in a terminal
window.
Patrick Dohmen
Manolis Surligas
George Vardakis
Manolis Surligas