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Major update:

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- The GNSS-SDR code-based Observable generation algorithm for GPS L1 C/A was migrated from common TX time to common RX time. One of the main reasons is that the common TX algorithm was incompatible with the standard RINEX observables, wich requires the oservables at the same time of reception.
- Using common Rx time, the code was simplified and now requires less memory due to the lack of symbol buffer

- Now it is possible to use standard RINEX post processing software (gpstk and rtklib for instance) to get PVT and the obtained precision is comparable to the internal Least Squares solver. It is possible to use also the carrier phase observable, but is still experimental.

- The default RINEX version output was set to 2.11 in this revision.  RINEX 3.00 is under verification now.


git-svn-id: https://svn.code.sf.net/p/gnss-sdr/code/trunk@364 64b25241-fba3-4117-9849-534c7e92360d
This commit is contained in:
Javier Arribas
2013-06-12 15:19:32 +00:00
parent 09c6ac095a
commit 3e87d1f204
12 changed files with 170 additions and 204 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l1_ca_telemetry_decoder_cc.cc
+10 -12
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@@ -118,7 +118,6 @@ gps_l1_ca_telemetry_decoder_cc::gps_l1_ca_telemetry_decoder_cc(
}
}
d_sample_counter = 0;
d_preamble_code_phase_seconds = 0;
d_stat = 0;
d_preamble_index = 0;
d_symbol_accumulator=0;
@@ -220,7 +219,6 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items, gr_vector_i
d_flag_preamble = true;
d_preamble_index = d_sample_counter; //record the preamble sample stamp (t_P)
d_preamble_time_seconds = in[0][0].Tracking_timestamp_secs;// - d_preamble_duration_seconds; //record the PRN start sample index associated to the preamble
d_preamble_code_phase_seconds = in[0][0].Code_phase_secs;
if (!d_flag_frame_sync)
{
@@ -306,18 +304,18 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items, gr_vector_i
//1. Copy the current tracking output
current_synchro_data=in[0][0];
//2. Add the telemetry decoder information
if (flag_TOW_set==true)
{
d_TOW_at_current_symbol=d_TOW_at_current_symbol+GPS_L1_CA_CODE_PERIOD;
}
if (this->d_flag_preamble==true and d_GPS_FSM.d_nav.d_TOW>0) //update TOW at the preamble instant (todo: check for valid d_TOW)
{
d_TOW_at_Preamble=d_GPS_FSM.d_nav.d_TOW+GPS_SUBFRAME_SECONDS; //we decoded the current TOW when the last word of the subframe arrive, so, we have a lag of ONE SUBFRAME
d_TOW_at_current_symbol=d_TOW_at_Preamble+GPS_CA_PREAMBLE_LENGTH_BITS/GPS_CA_TELEMETRY_RATE_BITS_SECOND;
Prn_timestamp_at_preamble_ms=in[0][0].Tracking_timestamp_secs * 1000.0;
if (flag_TOW_set==false)
{
d_TOW_at_current_symbol=d_TOW_at_Preamble+GPS_L1_CA_CODE_PERIOD*GPS_CA_PREAMBLE_LENGTH_BITS;
flag_TOW_set=true;
flag_TOW_set=true;
}
}else{
d_TOW_at_current_symbol=d_TOW_at_current_symbol+GPS_L1_CA_CODE_PERIOD;
}
@@ -325,20 +323,20 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items, gr_vector_i
current_synchro_data.d_TOW_at_current_symbol=d_TOW_at_current_symbol;
current_synchro_data.Flag_valid_word = (d_flag_frame_sync == true and d_flag_parity == true and flag_TOW_set==true);
current_synchro_data.Flag_preamble = d_flag_preamble;
current_synchro_data.Preamble_timestamp_ms = d_preamble_time_seconds * 1000.0;
current_synchro_data.Prn_timestamp_ms = in[0][0].Tracking_timestamp_secs * 1000.0;
current_synchro_data.Preamble_symbol_counter = 0;//fmod((double)(d_sample_counter - d_preamble_index), 6000); //not corrected the preamble correlation lag! -> to be taken into account in TX Time
current_synchro_data.Prn_timestamp_at_preamble_ms = Prn_timestamp_at_preamble_ms;
if(d_dump == true)
{
// MULTIPLEXED FILE RECORDING - Record results to file
try
{
double tmp_double;
tmp_double = current_synchro_data.Preamble_timestamp_ms;
tmp_double = d_TOW_at_current_symbol;
d_dump_file.write((char*)&tmp_double, sizeof(double));
tmp_double = current_synchro_data.Prn_timestamp_ms;
d_dump_file.write((char*)&tmp_double, sizeof(double));
tmp_double = current_synchro_data.Preamble_symbol_counter;
tmp_double = d_TOW_at_Preamble;
d_dump_file.write((char*)&tmp_double, sizeof(double));
}
catch (std::ifstream::failure e)
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l1_ca_telemetry_decoder_cc.h
+1 -1
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@@ -120,10 +120,10 @@ private:
//std::deque<double> d_prn_start_sample_history;
double d_preamble_time_seconds;
double d_preamble_code_phase_seconds;
double d_TOW_at_Preamble;
double d_TOW_at_current_symbol;
double Prn_timestamp_at_preamble_ms;
bool flag_TOW_set;
std::string d_dump_filename;