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Fix computation of time in the hybrid Galileo/GPS solution

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This commit is contained in:
Carles Fernandez 2016-05-10 21:19:09 +02:00
parent 3bd4547b57
commit fc7d3118c5
1 changed files with 14 additions and 20 deletions
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34
src/algorithms/PVT/libs/hybrid_ls_pvt.cc
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@ -69,8 +69,6 @@ hybrid_ls_pvt::hybrid_ls_pvt(int nchannels, std::string dump_filename, bool flag
}
hybrid_ls_pvt::~hybrid_ls_pvt()
{
d_dump_file.close();
@ -79,10 +77,6 @@ hybrid_ls_pvt::~hybrid_ls_pvt()
}
bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, double hybrid_current_time, bool flag_averaging)
{
std::map<int,Gnss_Synchro>::iterator gnss_pseudoranges_iter;
@ -115,10 +109,8 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
gnss_pseudoranges_iter != gnss_pseudoranges_map.end();
gnss_pseudoranges_iter++)
{
if (gnss_pseudoranges_iter->second.System == 'E')
if(gnss_pseudoranges_iter->second.System == 'E')
{
//std::cout << "Satellite System: " << gnss_pseudoranges_iter->second.System <<std::endl;
// 1 Gal - find the ephemeris for the current GALILEO SV observation. The SV PRN ID is the map key
galileo_ephemeris_iter = galileo_ephemeris_map.find(gnss_pseudoranges_iter->second.PRN);
if (galileo_ephemeris_iter != galileo_ephemeris_map.end())
@ -130,7 +122,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
// COMMON RX TIME PVT ALGORITHM
double Rx_time = hybrid_current_time;
double Tx_time = Rx_time - gnss_pseudoranges_iter->second.Pseudorange_m/GALILEO_C_m_s;
double Tx_time = Rx_time - gnss_pseudoranges_iter->second.Pseudorange_m / GALILEO_C_m_s;
// 2- compute the clock drift using the clock model (broadcast) for this SV
SV_clock_bias_s = galileo_ephemeris_iter->second.sv_clock_drift(Tx_time);
@ -144,7 +136,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
satpos(2,obs_counter) = galileo_ephemeris_iter->second.d_satpos_Z;
// 5- fill the observations vector with the corrected pseudoranges
obs(obs_counter) = gnss_pseudoranges_iter->second.Pseudorange_m + SV_clock_bias_s*GALILEO_C_m_s;
obs(obs_counter) = gnss_pseudoranges_iter->second.Pseudorange_m + SV_clock_bias_s * GALILEO_C_m_s;
d_visible_satellites_IDs[valid_obs] = galileo_ephemeris_iter->second.i_satellite_PRN;
d_visible_satellites_CN0_dB[valid_obs] = gnss_pseudoranges_iter->second.CN0_dB_hz;
valid_obs++;
@ -170,7 +162,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
}
}
else if (gnss_pseudoranges_iter->second.System == 'G')
else if(gnss_pseudoranges_iter->second.System == 'G')
{
//std::cout << "Satellite System: " << gnss_pseudoranges_iter->second.System <<std::endl;
// 1 GPS - find the ephemeris for the current GPS SV observation. The SV PRN ID is the map key
@ -185,7 +177,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
// COMMON RX TIME PVT ALGORITHM MODIFICATION (Like RINEX files)
// first estimate of transmit time
double Rx_time = hybrid_current_time;
double Tx_time = Rx_time - gnss_pseudoranges_iter->second.Pseudorange_m/GPS_C_m_s;
double Tx_time = Rx_time - gnss_pseudoranges_iter->second.Pseudorange_m / GPS_C_m_s;
// 2- compute the clock drift using the clock model (broadcast) for this SV
SV_clock_bias_s = gps_ephemeris_iter->second.sv_clock_drift(Tx_time);
@ -199,7 +191,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
satpos(2, obs_counter) = gps_ephemeris_iter->second.d_satpos_Z;
// 5- fill the observations vector with the corrected pseudorranges
obs(obs_counter) = gnss_pseudoranges_iter->second.Pseudorange_m + SV_clock_bias_s*GPS_C_m_s;
obs(obs_counter) = gnss_pseudoranges_iter->second.Pseudorange_m + SV_clock_bias_s * GPS_C_m_s;
d_visible_satellites_IDs[valid_obs] = gps_ephemeris_iter->second.i_satellite_PRN;
d_visible_satellites_CN0_dB[valid_obs] = gnss_pseudoranges_iter->second.CN0_dB_hz;
valid_obs++;
@ -232,15 +224,16 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
d_valid_GAL_obs = valid_obs_GALILEO_counter;
LOG(INFO) << "HYBRID PVT: valid observations=" << valid_obs;
if (valid_obs >= 4)
if(valid_obs >= 4)
{
arma::vec mypos;
DLOG(INFO) << "satpos=" << satpos;
DLOG(INFO) << "obs="<< obs;
DLOG(INFO) << "obs=" << obs;
DLOG(INFO) << "W=" << W;
mypos = leastSquarePos(satpos, obs, W);
d_rx_dt_m = mypos(3)/GPS_C_m_s; // Convert RX time offset from meters to seconds
double secondsperweek = 604800.0;
// Compute GST and Gregorian time
if( GST != 0.0)
{
@ -248,14 +241,15 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
}
else
{
utc = gps_utc_model.utc_time(TX_time_corrected_s, GPS_week);
utc = gps_utc_model.utc_time(TX_time_corrected_s, GPS_week) + secondsperweek * static_cast<double>(GPS_week);
}
// get time string Gregorian calendar
double secondsperweek = 604800.0; // number of seconds in one week (7*24*60*60)
boost::posix_time::time_duration t = boost::posix_time::seconds(utc + secondsperweek * static_cast<double>(GPS_week));
boost::posix_time::time_duration t = boost::posix_time::seconds(utc);
// 22 August 1999 00:00 last Galileo start GST epoch (ICD sec 5.1.2)
boost::posix_time::ptime p_time(boost::gregorian::date(1999, 8, 22), t);
d_position_UTC_time = p_time;
DLOG(INFO) << "HYBRID Position at TOW=" << hybrid_current_time << " in ECEF (X,Y,Z) = " << mypos;
cart2geo(static_cast<double>(mypos(0)), static_cast<double>(mypos(1)), static_cast<double>(mypos(2)), 4);
@ -310,7 +304,7 @@ bool hybrid_ls_pvt::get_PVT(std::map<int,Gnss_Synchro> gnss_pseudoranges_map, do
}
catch (const std::ifstream::failure& e)
{
LOG(WARNING) << "Exception writing PVT LS dump file "<< e.what();
LOG(WARNING) << "Exception writing PVT LS dump file " << e.what();
}
}