gr-satnogs/include/satnogs/doppler_correction_cc.h

67 lines
2.4 KiB
C++

/* -*- c++ -*- */
/*
* gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
*
* Copyright (C) 2016,2019 Libre Space Foundation <http://libre.space>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H
#define INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H
#include <satnogs/api.h>
#include <gnuradio/sync_block.h>
namespace gr {
namespace satnogs {
/*!
* \brief This block corrects the doppler effect between the ground
* station and the satellite. It takes the input stream in baseband
* and applies proper corrections to keep the carrier at the desired
* frequency. To achieve that it uses messages containing the absolute
* predicted frequency of the satellite from software like Gpredict.
*
* \ingroup satnogs
*
*/
class SATNOGS_API doppler_correction_cc : virtual public gr::sync_block {
public:
typedef boost::shared_ptr<doppler_correction_cc> sptr;
/*!
* The doppler correction block. The input is the complex signal at
* baseband as it comes from the SDR device. The message input \p freq
* received periodically messages containing the predicted absolute
* frequency of the satellite at that specific time.
* @param target_freq the absolute frequency of the satellite
* @param offset the frequency offset from the actual target frequency.
* This is very common on SDR receivers to avoid DC spikes at the center
* frequency. This block can automatically compensate this offset
* @param sampling_rate the sampling rate of the signal
* @param corrections_per_sec the number of the corrections every second
* that the block should perform
*/
static sptr
make(double target_freq, double offset, double sampling_rate,
size_t corrections_per_sec = 1000);
};
} // namespace satnogs
} // namespace gr
#endif /* INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H */