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Added Galileo E6 experimental Pseudorange generation using signal source timetag propagation

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This commit is contained in:
Javier Arribas 2022-05-23 15:34:06 +02:00
parent 742113c55f
commit 67e4d7c6e2
2 changed files with 26 additions and 1 deletions
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26
src/algorithms/telemetry_decoder/gnuradio_blocks/galileo_telemetry_decoder_gs.cc
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@ -85,7 +85,8 @@ galileo_telemetry_decoder_gs::galileo_telemetry_decoder_gs(
d_enable_navdata_monitor(conf.enable_navdata_monitor), d_enable_navdata_monitor(conf.enable_navdata_monitor),
d_dump_crc_stats(conf.dump_crc_stats), d_dump_crc_stats(conf.dump_crc_stats),
d_enable_reed_solomon_inav(false), d_enable_reed_solomon_inav(false),
d_valid_timetag(false) d_valid_timetag(false),
d_E6_TOW_set(false)
{ {
// prevent telemetry symbols accumulation in output buffers // prevent telemetry symbols accumulation in output buffers
this->set_max_noutput_items(1); this->set_max_noutput_items(1);
@ -591,6 +592,7 @@ void galileo_telemetry_decoder_gs::set_satellite(const Gnss_Satellite &satellite
d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN()); d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN());
d_last_valid_preamble = d_sample_counter; d_last_valid_preamble = d_sample_counter;
d_sent_tlm_failed_msg = false; d_sent_tlm_failed_msg = false;
d_E6_TOW_set = false;
DLOG(INFO) << "Setting decoder Finite State Machine to satellite " << d_satellite; DLOG(INFO) << "Setting decoder Finite State Machine to satellite " << d_satellite;
DLOG(INFO) << "Navigation Satellite set to " << d_satellite; DLOG(INFO) << "Navigation Satellite set to " << d_satellite;
} }
@ -607,6 +609,7 @@ void galileo_telemetry_decoder_gs::reset()
d_inav_nav.set_TOW0_flag(false); d_inav_nav.set_TOW0_flag(false);
d_last_valid_preamble = d_sample_counter; d_last_valid_preamble = d_sample_counter;
d_sent_tlm_failed_msg = false; d_sent_tlm_failed_msg = false;
d_E6_TOW_set = false;
d_stat = 0; d_stat = 0;
d_viterbi->reset(); d_viterbi->reset();
if (d_enable_reed_solomon_inav == true) if (d_enable_reed_solomon_inav == true)
@ -1019,6 +1022,23 @@ int galileo_telemetry_decoder_gs::general_work(int noutput_items __attribute__((
case 3: // CNAV case 3: // CNAV
{ {
// TODO // TODO
// Obtain Galileo E6 TOW from timetags, if available
if (d_valid_timetag == true)
{
int rx_tow_at_preamble = d_current_timetag.tow_ms;
uint32_t predicted_tow_at_preamble_ms = 1000 * (rx_tow_at_preamble / 1000); // floor to integer number of seconds
d_TOW_at_Preamble_ms = predicted_tow_at_preamble_ms;
//todo: compute tow at current symbol from the decoder delay similar as d_TOW_at_current_symbol_ms = d_TOW_at_Preamble_ms + static_cast<uint32_t>((d_required_symbols + 1) * GALILEO_FNAV_CODES_PER_SYMBOL * GALILEO_E5A_CODE_PERIOD_MS);
d_TOW_at_current_symbol_ms = predicted_tow_at_preamble_ms + static_cast<uint32_t>((GALILEO_CNAV_SYMBOLS_PER_PAGE - GALILEO_CNAV_PREAMBLE_LENGTH_BITS) * d_PRN_code_period_ms);
if (d_E6_TOW_set == false)
{
std::cout << " Sat PRN " << d_satellite.get_PRN() << " E6 TimeTag TOW at preamble: " << predicted_tow_at_preamble_ms
// << " [ms] TOW fraction: " << d_current_timetag.tow_ms_fraction
<< " [ms] d_TOW_at_current_symbol_ms: " << d_TOW_at_current_symbol_ms << " [ms]\n";
d_E6_TOW_set = true;
}
}
} }
} }
} }
@ -1078,6 +1098,10 @@ int galileo_telemetry_decoder_gs::general_work(int noutput_items __attribute__((
case 3: // CNAV case 3: // CNAV
{ {
// TODO // TODO
if (d_E6_TOW_set == true)
{
current_symbol.Flag_valid_word = true;
}
break; break;
} }
} }

1
src/algorithms/telemetry_decoder/gnuradio_blocks/galileo_telemetry_decoder_gs.h
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@ -147,6 +147,7 @@ private:
bool d_dump_crc_stats; bool d_dump_crc_stats;
bool d_enable_reed_solomon_inav; bool d_enable_reed_solomon_inav;
bool d_valid_timetag; bool d_valid_timetag;
bool d_E6_TOW_set;
}; };