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Fix observables clock drift bug (Candidate one)

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This commit is contained in:
Javier Arribas
2018-05-18 21:07:12 +02:00
parent 2b7663e70c
commit 6d4a89148a
3 changed files with 38 additions and 24 deletions
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38
src/algorithms/observables/gnuradio_blocks/hybrid_observables_cc.cc
View File

@@ -87,6 +87,8 @@ hybrid_observables_cc::hybrid_observables_cc(unsigned int nchannels_in,
}
}
}
T_rx_TOW_s=0.0;
T_rx_TOW_set=false;
}
@@ -316,10 +318,6 @@ bool hybrid_observables_cc::interpolate_data(Gnss_Synchro &out, const unsigned i
// CARRIER DOPPLER INTERPOLATION
out.Carrier_Doppler_hz = d_gnss_synchro_history->at(ch, 0).Carrier_Doppler_hz + (d_gnss_synchro_history->at(ch, 1).Carrier_Doppler_hz - d_gnss_synchro_history->at(ch, 0).Carrier_Doppler_hz) * (ti - d_gnss_synchro_history->at(ch, 0).RX_time) / (d_gnss_synchro_history->at(ch, 1).RX_time - d_gnss_synchro_history->at(ch, 0).RX_time);
// todo: CODE PHASE IS MISSING!
// todo: convert to seconds, considering fs per channel
out.Code_phase_samples = d_gnss_synchro_history->at(ch, 0).Code_phase_samples + (d_gnss_synchro_history->at(ch, 1).Code_phase_samples - d_gnss_synchro_history->at(ch, 0).Code_phase_samples) * (ti - d_gnss_synchro_history->at(ch, 0).RX_time) / (d_gnss_synchro_history->at(ch, 1).RX_time - d_gnss_synchro_history->at(ch, 0).RX_time);
// TOW INTERPOLATION
out.TOW_at_current_symbol_s = d_gnss_synchro_history->at(ch, 0).TOW_at_current_symbol_s + (d_gnss_synchro_history->at(ch, 1).TOW_at_current_symbol_s - d_gnss_synchro_history->at(ch, 0).TOW_at_current_symbol_s) * (ti - d_gnss_synchro_history->at(ch, 0).RX_time) / (d_gnss_synchro_history->at(ch, 1).RX_time - d_gnss_synchro_history->at(ch, 0).RX_time);
@@ -436,24 +434,26 @@ void hybrid_observables_cc::correct_TOW_and_compute_prange(std::vector<Gnss_Sync
}
#endif
///////////////////////////////////////////////////////////
double TOW_ref = std::numeric_limits<double>::lowest();
double Code_phase_ref_s = 0.0;
if (!T_rx_TOW_set)
{
for (it = data.begin(); it != data.end(); it++)
{
if (it->TOW_at_current_symbol_s > TOW_ref)
{
TOW_ref = it->TOW_at_current_symbol_s;
}
}
T_rx_TOW_s=round(TOW_ref*1000.0)/1000.0;
T_rx_TOW_set=true;
}else{
T_rx_TOW_s+=T_rx_step_s;
TOW_ref=T_rx_TOW_s;
}
for (it = data.begin(); it != data.end(); it++)
{
if (it->TOW_at_current_symbol_s > TOW_ref)
{
TOW_ref = it->TOW_at_current_symbol_s;
Code_phase_ref_s = it->Code_phase_samples / static_cast<double>(it->fs);
}
}
for (it = data.begin(); it != data.end(); it++)
{
//double traveltime_s = TOW_ref - it->TOW_at_current_symbol_s + GPS_STARTOFFSET_ms / 1000.0;
double traveltime_s = TOW_ref - it->TOW_at_current_symbol_s + Code_phase_ref_s - it->Code_phase_samples / static_cast<double>(it->fs) + GPS_STARTOFFSET_ms / 1000.0;
//it->RX_time = TOW_ref + GPS_STARTOFFSET_ms / 1000.0;
it->RX_time = TOW_ref + Code_phase_ref_s + GPS_STARTOFFSET_ms / 1000.0;
double traveltime_s = TOW_ref - it->TOW_at_current_symbol_s + GPS_STARTOFFSET_ms / 1000.0;
it->RX_time = TOW_ref + GPS_STARTOFFSET_ms / 1000.0;
it->Pseudorange_m = traveltime_s * SPEED_OF_LIGHT;
}
}

3
src/algorithms/observables/gnuradio_blocks/hybrid_observables_cc.h
View File

@@ -77,6 +77,9 @@ private:
boost::dynamic_bitset<> valid_channels;
double T_rx_s;
double T_rx_step_s;
//rx time follow GPST
bool T_rx_TOW_set;
double T_rx_TOW_s;
double max_delta;
double d_latency;
bool d_dump;