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Removing unused code, improving ref satellite selection in observables and partial correction of the gps L2 TOW offset bug

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This commit is contained in:
Javier Arribas
2017-03-30 19:25:46 +02:00
parent b745ebf0a8
commit e0b0605545
9 changed files with 436 additions and 441 deletions
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12
conf/gnss-sdr_multichannel_GPS_L2_M_Flexiband_bin_file_III_1b.conf
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@@ -268,12 +268,12 @@ Resampler2.implementation=Pass_Through
;######### CHANNELS GLOBAL CONFIG ############
;#count: Number of available GPS satellite channels.
Channels_1C.count=0
Channels_2S.count=13
Channels_2S.count=11
;#GPS.prns=7,8
;#in_acquisition: Number of channels simultaneously acquiring for the whole receiver
Channels.in_acquisition=12
Channels.in_acquisition=10
;# signal:
;# "1C" GPS L1 C/A
@@ -293,7 +293,7 @@ Channel6.RF_channel_ID=1
Channel7.RF_channel_ID=1
Channel8.RF_channel_ID=1
Channel9.RF_channel_ID=1
Channel10.RF_channel_ID=1
Channel10.RF_channel_ID=0
Channel11.RF_channel_ID=1
Channel12.RF_channel_ID=0
Channel13.RF_channel_ID=1
@@ -349,7 +349,7 @@ Tracking_1C.early_late_space_chips=0.5;
Tracking_2S.implementation=GPS_L2_M_DLL_PLL_Tracking
Tracking_2S.item_type=gr_complex
Tracking_2S.if=0
Tracking_2S.dump=false
Tracking_2S.dump=true
Tracking_2S.dump_filename=./tracking_ch_
Tracking_2S.pll_bw_hz=2.0;
Tracking_2S.dll_bw_hz=0.25;
@@ -360,7 +360,7 @@ Tracking_2S.early_late_space_chips=0.5;
;######### TELEMETRY DECODER CONFIG ############
TelemetryDecoder_1C.implementation=GPS_L1_CA_Telemetry_Decoder
TelemetryDecoder_1C.dump=false
TelemetryDecoder_1C.decimation_factor=20;
TelemetryDecoder_1C.decimation_factor=1;
TelemetryDecoder_2S.implementation=GPS_L2C_Telemetry_Decoder
TelemetryDecoder_2S.dump=false
@@ -372,7 +372,7 @@ TelemetryDecoder_2S.decimation_factor=1;
Observables.implementation=Hybrid_Observables
;#dump: Enable or disable the Observables internal binary data file logging [true] or [false]
Observables.dump=false
Observables.dump=true
;#dump_filename: Log path and filename.
Observables.dump_filename=./observables.dat

14
src/algorithms/observables/gnuradio_blocks/hybrid_observables_cc.cc
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@@ -100,9 +100,16 @@ hybrid_observables_cc::~hybrid_observables_cc()
bool Hybrid_pairCompare_gnss_synchro_d_TOW_at_current_symbol(const std::pair<int,Gnss_Synchro>& a, const std::pair<int,Gnss_Synchro>& b)
{
if (a.second.d_TOW_at_current_symbol==b.second.d_TOW_at_current_symbol)
{
return (a.second.Prn_timestamp_ms/1000.0) > (b.second.Prn_timestamp_ms/1000.0);
}else{
return (a.second.d_TOW_at_current_symbol) < (b.second.d_TOW_at_current_symbol);
}
}
int hybrid_observables_cc::general_work (int noutput_items,
gr_vector_int &ninput_items,
@@ -179,6 +186,7 @@ int hybrid_observables_cc::general_work (int noutput_items,
// what is the most recent symbol TOW in the current set? -> this will be the reference symbol
gnss_synchro_iter = max_element(current_gnss_synchro_map.begin(), current_gnss_synchro_map.end(), Hybrid_pairCompare_gnss_synchro_d_TOW_at_current_symbol);
double d_TOW_reference = gnss_synchro_iter->second.d_TOW_at_current_symbol;
//std::cout<<"OBS SV REF SAT: "<<gnss_synchro_iter->second.PRN<<std::endl;
double d_ref_PRN_rx_time_ms = gnss_synchro_iter->second.Prn_timestamp_ms;
// Now compute RX time differences due to the PRN alignment in the correlators
@@ -196,6 +204,10 @@ int hybrid_observables_cc::general_work (int noutput_items,
+ GPS_STARTOFFSET_ms;
//convert to meters
pseudorange_m = traveltime_ms * GPS_C_m_ms; // [m]
//std::cout<<"["<<gnss_synchro_iter->second.PRN<<"] delta_rx_t: "<<delta_rx_time_ms
// <<" [ms] delta_TOW_ms: "<<(d_TOW_reference - gnss_synchro_iter->second.d_TOW_at_current_symbol) * 1000.0
// <<" Pr: "<<pseudorange_m<<" [m]"
// <<std::endl;
// update the pseudorange object
current_gnss_synchro[gnss_synchro_iter->second.Channel_ID] = gnss_synchro_iter->second;
current_gnss_synchro[gnss_synchro_iter->second.Channel_ID].Pseudorange_m = pseudorange_m;
@@ -246,6 +258,8 @@ int hybrid_observables_cc::general_work (int noutput_items,
double tmp_double;
for (unsigned int i = 0; i < d_nchannels; i++)
{
tmp_double = current_gnss_synchro[i].RX_time;
d_dump_file.write((char*)&tmp_double, sizeof(double));
tmp_double = current_gnss_synchro[i].d_TOW_at_current_symbol;
d_dump_file.write((char*)&tmp_double, sizeof(double));
tmp_double = current_gnss_synchro[i].Carrier_Doppler_hz;

9
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l2c_telemetry_decoder_cc.cc
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@@ -154,22 +154,19 @@ int gps_l2c_telemetry_decoder_cc::general_work (int noutput_items __attribute__(
//* delay by the formulae:
//* \code
//* symbolTime_ms = msg->tow * 6000 + *pdelay * 20
d_TOW_at_current_symbol=((double)msg.tow) * 6.0 + ((double)delay) * GPS_L2_M_PERIOD +GPS_L2_M_PERIOD;
current_synchro_data.d_TOW_at_current_symbol = d_TOW_at_current_symbol;
current_synchro_data.Prn_timestamp_ms = in[0].Tracking_timestamp_secs * 1000.0;
d_TOW_at_current_symbol=((double)msg.tow) * 6.0 + ((double)delay) * GPS_L2_M_PERIOD +12*GPS_L2_M_PERIOD;
d_flag_valid_word=true;
}
else
{
d_TOW_at_current_symbol +=GPS_L2_M_PERIOD;
current_synchro_data.d_TOW_at_current_symbol = d_TOW_at_current_symbol;
current_synchro_data.Prn_timestamp_ms = in[0].Tracking_timestamp_secs * 1000.0;
if (current_synchro_data.Flag_valid_symbol_output==false)
{
d_flag_valid_word=false;
}
}
current_synchro_data.d_TOW_at_current_symbol = d_TOW_at_current_symbol;
current_synchro_data.Prn_timestamp_ms = in[0].Tracking_timestamp_secs * 1000.0;
current_synchro_data.Flag_valid_word=d_flag_valid_word;
// if (flag_PLL_180_deg_phase_locked == true)

3
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_cc.cc
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@@ -539,7 +539,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_cc::general_work (int noutput_items __attri
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -559,7 +558,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_cc::general_work (int noutput_items __attri
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;// todo: project the carrier doppler
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -574,7 +572,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_cc::general_work (int noutput_items __attri
current_synchro_data.System = {'G'};
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
}
//assign the GNURadio block output data
*out[0] = current_synchro_data;

3
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc.cc
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@@ -534,7 +534,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc::general_work (int noutput_items __
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -554,7 +553,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc::general_work (int noutput_items __
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;// todo: project the carrier doppler
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -569,7 +567,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc::general_work (int noutput_items __
current_synchro_data.System = {'G'};
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
}
*out[0] = current_synchro_data;
if(d_dump)

3
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_sc.cc
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@@ -542,7 +542,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_sc::general_work (int noutput_items __attri
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -562,7 +561,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_sc::general_work (int noutput_items __attri
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs_16sc[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample (Hybridization OK!)
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + d_rem_code_phase_samples) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = GPS_TWO_PI * d_acc_carrier_phase_cycles;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;// todo: project the carrier doppler
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -577,7 +575,6 @@ int gps_l1_ca_dll_pll_c_aid_tracking_sc::general_work (int noutput_items __attri
current_synchro_data.System = {'G'};
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + d_correlation_length_samples + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
}
*out[0] = current_synchro_data;
if(d_dump)

4
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc
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@@ -407,10 +407,8 @@ int Gps_L1_Ca_Dll_Pll_Tracking_cc::general_work (int noutput_items __attribute__
// ########### Output the tracking data to navigation and PVT ##########
current_synchro_data.Prompt_I = static_cast<double>((d_correlator_outs[1]).real());
current_synchro_data.Prompt_Q = static_cast<double>((d_correlator_outs[1]).imag());
// Tracking_timestamp_secs is aligned with the CURRENT PRN start sample
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter + d_current_prn_length_samples) + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
current_synchro_data.CN0_dB_hz = d_CN0_SNV_dB_Hz;
@@ -425,7 +423,6 @@ int Gps_L1_Ca_Dll_Pll_Tracking_cc::general_work (int noutput_items __attribute__
}
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter + d_current_prn_length_samples) + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
current_synchro_data.Rem_code_phase_secs = d_rem_code_phase_samples / static_cast<double>(d_fs_in);
current_synchro_data.System = {'G'};
}
@@ -489,7 +486,6 @@ int Gps_L1_Ca_Dll_Pll_Tracking_cc::general_work (int noutput_items __attribute__
consume_each(d_current_prn_length_samples); // this is necessary in gr::block derivates
d_sample_counter += d_current_prn_length_samples; // count for the processed samples
return 1; // output tracking result ALWAYS even in the case of d_enable_tracking==false
}

44
src/algorithms/tracking/gnuradio_blocks/gps_l2_m_dll_pll_tracking_cc.cc
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@@ -110,6 +110,8 @@ gps_l2_m_dll_pll_tracking_cc::gps_l2_m_dll_pll_tracking_cc(
d_vector_length = vector_length;
d_dump_filename = dump_filename;
d_current_prn_length_samples = static_cast<int>(d_vector_length);
// DLL/PLL filter initialization
d_carrier_loop_filter=Tracking_2nd_PLL_filter(GPS_L2_M_PERIOD);
d_code_loop_filter=Tracking_2nd_DLL_filter(GPS_L2_M_PERIOD);
@@ -138,8 +140,7 @@ gps_l2_m_dll_pll_tracking_cc::gps_l2_m_dll_pll_tracking_cc(
d_local_code_shift_chips[1] = 0.0;
d_local_code_shift_chips[2] = d_early_late_spc_chips;
multicorrelator_cpu.init(2 * d_vector_length, d_n_correlator_taps);
multicorrelator_cpu.init(2 * d_current_prn_length_samples, d_n_correlator_taps);
//--- Perform initializations ------------------------------
// define initial code frequency basis of NCO
@@ -157,8 +158,6 @@ gps_l2_m_dll_pll_tracking_cc::gps_l2_m_dll_pll_tracking_cc(
d_enable_tracking = false;
d_pull_in = false;
d_current_prn_length_samples = static_cast<int>(d_vector_length);
// CN0 estimation and lock detector buffers
d_cn0_estimation_counter = 0;
d_Prompt_buffer = new gr_complex[GPS_L2M_CN0_ESTIMATION_SAMPLES];
@@ -169,7 +168,6 @@ gps_l2_m_dll_pll_tracking_cc::gps_l2_m_dll_pll_tracking_cc(
systemName["G"] = std::string("GPS");
set_relative_rate(1.0/((double)d_vector_length*2));
//set_min_output_buffer((long int)300);
d_acquisition_gnss_synchro = 0;
@@ -184,7 +182,7 @@ gps_l2_m_dll_pll_tracking_cc::gps_l2_m_dll_pll_tracking_cc(
d_code_phase_step_chips = 0.0;
d_carrier_phase_step_rad = 0.0;
LOG(INFO) << "d_vector_length" << d_vector_length;
set_relative_rate(1.0 / static_cast<double>(d_vector_length));
}
@@ -198,9 +196,9 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
d_acq_sample_stamp = d_acquisition_gnss_synchro->Acq_samplestamp_samples;
long int acq_trk_diff_samples;
float acq_trk_diff_seconds;
double acq_trk_diff_seconds;
acq_trk_diff_samples = static_cast<long int>(d_sample_counter) - static_cast<long int>(d_acq_sample_stamp); //-d_vector_length;
LOG(INFO) << "Number of samples between Acquisition and Tracking =" << acq_trk_diff_samples;
DLOG(INFO) << "Number of samples between Acquisition and Tracking =" << acq_trk_diff_samples;
acq_trk_diff_seconds = static_cast<float>(acq_trk_diff_samples) / static_cast<float>(d_fs_in);
// Doppler effect
// Fd=(C/(C+Vr))*F
@@ -213,23 +211,23 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
d_code_phase_step_chips = static_cast<double>(d_code_freq_chips) / static_cast<double>(d_fs_in);
T_chip_mod_seconds = 1/d_code_freq_chips;
T_prn_mod_seconds = T_chip_mod_seconds * GPS_L2_M_CODE_LENGTH_CHIPS;
T_prn_mod_samples = T_prn_mod_seconds * static_cast<float>(d_fs_in);
T_prn_mod_samples = T_prn_mod_seconds * static_cast<double>(d_fs_in);
d_current_prn_length_samples = round(T_prn_mod_samples);
double T_prn_true_seconds = GPS_L2_M_CODE_LENGTH_CHIPS / GPS_L2_M_CODE_RATE_HZ;
double T_prn_true_samples = T_prn_true_seconds * static_cast<float>(d_fs_in);
double T_prn_true_samples = T_prn_true_seconds * static_cast<double>(d_fs_in);
double T_prn_diff_seconds = T_prn_true_seconds - T_prn_mod_seconds;
double N_prn_diff = acq_trk_diff_seconds / T_prn_true_seconds;
double corrected_acq_phase_samples, delay_correction_samples;
corrected_acq_phase_samples = fmod((d_acq_code_phase_samples + T_prn_diff_seconds * N_prn_diff * static_cast<float>(d_fs_in)), T_prn_true_samples);
corrected_acq_phase_samples = fmod((d_acq_code_phase_samples + T_prn_diff_seconds * N_prn_diff * static_cast<double>(d_fs_in)), T_prn_true_samples);
if (corrected_acq_phase_samples < 0)
{
corrected_acq_phase_samples = T_prn_mod_samples + corrected_acq_phase_samples;
}
delay_correction_samples = d_acq_code_phase_samples - corrected_acq_phase_samples;
//TODO: debug the algorithm implementation and enable correction
//d_acq_code_phase_samples = corrected_acq_phase_samples;
d_acq_code_phase_samples = corrected_acq_phase_samples;
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
d_carrier_phase_step_rad = GPS_L2_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
@@ -249,9 +247,9 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
d_carrier_lock_fail_counter = 0;
d_rem_code_phase_samples = 0;
d_rem_carr_phase_rad = 0;
d_rem_carr_phase_rad = 0.0;
d_rem_code_phase_chips = 0.0;
d_acc_carrier_phase_rad = 0;
d_acc_carrier_phase_rad = 0.0;
d_code_phase_samples = d_acq_code_phase_samples;
@@ -259,10 +257,9 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
sys = sys_.substr(0,1);
// DEBUG OUTPUT
std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) <<" whith Doppler="<<d_acq_carrier_doppler_hz<<" [Hz]"<< std::endl;
std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << std::endl;
LOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
// enable tracking
d_pull_in = true;
d_enable_tracking = true;
@@ -312,16 +309,17 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items __attribute__(
int samples_offset;
double acq_trk_shif_correction_samples;
int acq_to_trk_delay_samples;
acq_to_trk_delay_samples = (d_sample_counter - (d_acq_sample_stamp-d_current_prn_length_samples));
acq_trk_shif_correction_samples = -fmod(static_cast<float>(acq_to_trk_delay_samples), static_cast<float>(d_current_prn_length_samples));
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);//+(1.5*(d_fs_in/GPS_L2_M_CODE_RATE_HZ)));
acq_to_trk_delay_samples = d_sample_counter - d_acq_sample_stamp;
acq_trk_shif_correction_samples = d_current_prn_length_samples - fmod(static_cast<float>(acq_to_trk_delay_samples), static_cast<float>(d_current_prn_length_samples));
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
current_synchro_data.Tracking_timestamp_secs = (static_cast<double>(d_sample_counter) + static_cast<double>(d_rem_code_phase_samples)) / static_cast<double>(d_fs_in);
d_sample_counter = d_sample_counter + samples_offset; // count for the processed samples
d_pull_in = false;
// take into account the carrier cycles accumulated in the pull in signal alignment
d_acc_carrier_phase_rad -= d_carrier_phase_step_rad * samples_offset;
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;
*out[0] = current_synchro_data;
d_pull_in = false;
consume_each(samples_offset); // shift input to perform alignment with local replica
return 1;
}
@@ -337,6 +335,7 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items __attribute__(
// ################## PLL ##########################################################
// PLL discriminator
// Update PLL discriminator [rads/Ti -> Secs/Ti]
carr_error_hz = pll_cloop_two_quadrant_atan(d_correlator_outs[1]) / GPS_L2_TWO_PI;
// Carrier discriminator filter
carr_error_filt_hz = d_carrier_loop_filter.get_carrier_nco(carr_error_hz);
@@ -350,13 +349,12 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items __attribute__(
code_error_chips = dll_nc_e_minus_l_normalized(d_correlator_outs[0], d_correlator_outs[2]); // [chips/Ti]
// Code discriminator filter
code_error_filt_chips = d_code_loop_filter.get_code_nco(code_error_chips); //[chips/second]
//Code phase accumulator
double code_error_filt_secs = (GPS_L2_M_PERIOD * code_error_filt_chips) / GPS_L2_M_CODE_RATE_HZ; //[seconds]
// ################## CARRIER AND CODE NCO BUFFER ALIGNEMENT #######################
// keep alignment parameters for the next input buffer
// Compute the next buffer length based in the new period of the PRN sequence and the code phase error estimation
double T_chip_seconds = 1.0 / d_code_freq_chips;
double T_chip_seconds = 1.0 / static_cast<double>(d_code_freq_chips);
double T_prn_seconds = T_chip_seconds * GPS_L2_M_CODE_LENGTH_CHIPS;
double T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
double K_blk_samples = T_prn_samples + d_rem_code_phase_samples + code_error_filt_secs * static_cast<double>(d_fs_in);

1
src/core/system_parameters/gnss_synchro.h
View File

@@ -58,7 +58,6 @@ public:
double Carrier_Doppler_hz; //!< Set by Tracking processing block
double Carrier_phase_rads; //!< Set by Tracking processing block
double Tracking_timestamp_secs; //!< Set by Tracking processing block
double Rem_code_phase_secs; //!< Set by Tracking processing block
bool Flag_valid_symbol_output; //!< Set by Tracking processing block
int correlation_length_ms; //!< Set by Tracking processing block