GNU Radio's SATELLITES Package
doppler_correction_impl.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2022-2023 Daniel Estevez <daniel@destevez.net>.
4  *
5  * This file is part of gr-satellites
6  *
7  * SPDX-License-Identifier: GPL-3.0-or-later
8  */
9 
10 #ifndef INCLUDED_SATELLITES_DOPPLER_CORRECTION_IMPL_H
11 #define INCLUDED_SATELLITES_DOPPLER_CORRECTION_IMPL_H
12 
13 #include <gnuradio/math.h>
15 #include <cstdint>
16 #include <vector>
17 
18 namespace gr {
19 namespace satellites {
20 
22 {
23 private:
24  double d_phase;
25  double d_samp_rate;
26  size_t d_current_index;
27  double d_t0;
28  uint64_t d_sample_t0;
29  std::vector<double> times;
30  std::vector<double> freqs_rad_per_sample;
31  std::vector<tag_t> d_tags;
32 
33  // Used by UHD
34  const pmt::pmt_t d_rx_time_key;
35 
36  // Used by gr-difi
37  const pmt::pmt_t d_pck_n_key;
38  const pmt::pmt_t d_full_key;
39  const pmt::pmt_t d_frac_key;
40 
41  double d_current_time;
42  double d_current_freq;
43 
44  // Implementation taken from gr::block::control_loop
45  void phase_wrap()
46  {
47  while (d_phase > (2 * GR_M_PI))
48  d_phase -= 2 * GR_M_PI;
49  while (d_phase < (-2 * GR_M_PI))
50  d_phase += 2 * GR_M_PI;
51  }
52 
53  // Called after a time update. Makes the current index go backwards if
54  // needed because of a time update "to the past".
55  void adjust_current_index()
56  {
57  while ((d_current_index > 0) && (times[d_current_index] > d_t0)) {
58  --d_current_index;
59  }
60  }
61 
62  void read_doppler_file(const char* filename);
63 
64 public:
65  doppler_correction_impl(const char* filename, double samp_rate, double t0);
67 
68  void set_time(double) override;
69 
70  double time() override
71  {
72  gr::thread::scoped_lock guard(d_setlock);
73  return d_current_time;
74  }
75 
76  double frequency() override
77  {
78  gr::thread::scoped_lock guard(d_setlock);
79  return d_current_freq * d_samp_rate / (2.0 * GR_M_PI);
80  }
81 
82  int work(int noutput_items,
83  gr_vector_const_void_star& input_items,
84  gr_vector_void_star& output_items) override;
85 };
86 
87 } // namespace satellites
88 } // namespace gr
89 
90 #endif /* INCLUDED_SATELLITES_DOPPLER_CORRECTION_IMPL_H */
Definition: doppler_correction_impl.h:22
doppler_correction_impl(const char *filename, double samp_rate, double t0)
int work(int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) override
double frequency() override
Returns the current frequency in Hz.
Definition: doppler_correction_impl.h:76
void set_time(double) override
Sets the current time.
double time() override
Returns the current time.
Definition: doppler_correction_impl.h:70
Performs Doppler correction using a frequency vs. time file.
Definition: doppler_correction.h:46
Definition: ax100_decode.h:17