gnss-sdr/src/algorithms/PVT/libs/hybrid_ls_pvt.cc

345 lines
18 KiB
C++

/*!
* \file galileo_e1_ls_pvt.cc
* \brief Implementation of a Least Squares Position, Velocity, and Time
* (PVT) solver, based on K.Borre's Matlab receiver.
* \author Javier Arribas, 2011. jarribas(at)cttc.es
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "hybrid_ls_pvt.h"
#include <glog/logging.h>
#include "Galileo_E1.h"
using google::LogMessage;
hybrid_ls_pvt::hybrid_ls_pvt(int nchannels, std::string dump_filename, bool flag_dump_to_file) : Ls_Pvt()
{
// init empty ephemeris for all the available GNSS channels
d_nchannels = nchannels;
d_Gal_ephemeris = new Galileo_Navigation_Message[nchannels];
d_GPS_ephemeris = new Gps_Navigation_Message[nchannels];
d_dump_filename = dump_filename;
d_flag_dump_enabled = flag_dump_to_file;
d_galileo_current_time = 0;
d_valid_GPS_obs = 0;
d_valid_GAL_obs = 0;
count_valid_position = 0;
d_flag_averaging = false;
// ############# ENABLE DATA FILE LOG #################
if (d_flag_dump_enabled == true)
{
if (d_dump_file.is_open() == false)
{
try
{
d_dump_file.exceptions (std::ifstream::failbit | std::ifstream::badbit);
d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary);
LOG(INFO) << "PVT lib dump enabled Log file: " << d_dump_filename.c_str();
}
catch (std::ifstream::failure e)
{
LOG(WARNING) << "Exception opening PVT lib dump file " << e.what();
}
}
}
}
hybrid_ls_pvt::~hybrid_ls_pvt()
{
d_dump_file.close();
delete[] d_Gal_ephemeris;
delete[] d_GPS_ephemeris;
}
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;
std::map<int,Galileo_Ephemeris>::iterator galileo_ephemeris_iter;
std::map<int,Gps_Ephemeris>::iterator gps_ephemeris_iter;
int valid_pseudoranges = gnss_pseudoranges_map.size();
arma::mat W = arma::eye(valid_pseudoranges, valid_pseudoranges); // channels weights matrix
arma::vec obs = arma::zeros(valid_pseudoranges); // pseudoranges observation vector
arma::mat satpos = arma::zeros(3, valid_pseudoranges); // satellite positions matrix
int Galileo_week_number = 0;
int GPS_week;
double utc = 0;
double utc_tx_corrected = 0; //utc computed at tx_time_corrected, added for Galileo constellation (in GPS utc is directly computed at TX_time_corrected_s)
double TX_time_corrected_s;
double SV_clock_bias_s = 0;
d_flag_averaging = flag_averaging;
// ********************************************************************************
// ****** PREPARE THE LEAST SQUARES DATA (SV POSITIONS MATRIX AND OBS VECTORS) ****
// ********************************************************************************
int valid_obs = 0; //valid observations counter
int obs_counter = 0;
int valid_obs_GPS_counter = 0;
int valid_obs_GALILEO_counter = 0;
for(gnss_pseudoranges_iter = gnss_pseudoranges_map.begin();
gnss_pseudoranges_iter != gnss_pseudoranges_map.end();
gnss_pseudoranges_iter++)
{
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->first);
if (galileo_ephemeris_iter != galileo_ephemeris_map.end())
{
/*!
* \todo Place here the satellite CN0 (power level, or weight factor)
*/
W(obs_counter, obs_counter) = 1;
// COMMON RX TIME PVT ALGORITHM MODIFICATION (Like RINEX files)
// first estimate of transmit time
//Galileo_week_number = galileo_ephemeris_iter->second.WN_5;//for GST
//double sec_in_day = 86400;
//double day_in_week = 7;
// t = WN*sec_in_day*day_in_week + TOW; // t is Galileo System Time to use to compute satellite positions
double Rx_time = hybrid_current_time;
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);
// 3- compute the current ECEF position for this SV using corrected TX time
TX_time_corrected_s = Tx_time - SV_clock_bias_s;
galileo_ephemeris_iter->second.satellitePosition(TX_time_corrected_s);
satpos(0,obs_counter) = galileo_ephemeris_iter->second.d_satpos_X;
satpos(1,obs_counter) = galileo_ephemeris_iter->second.d_satpos_Y;
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;
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++;
valid_obs_GALILEO_counter ++;
Galileo_week_number = galileo_ephemeris_iter->second.WN_5; //for GST
//debug
double GST = galileo_ephemeris_iter->second.Galileo_System_Time(Galileo_week_number, hybrid_current_time);
utc = galileo_utc_model.GST_to_UTC_time(GST, Galileo_week_number); // this shoud be removed and it should be considered the utc_tx_corrected
utc_tx_corrected = galileo_utc_model.GST_to_UTC_time(TX_time_corrected_s, Galileo_week_number);
//std::cout<<"Gal UTC at TX_time_corrected_s = "<<utc_tx_corrected<< std::endl;
//std::cout<<"Gal_week = "<<Galileo_week_number<< std::endl;
//std::cout << "Gal UTC = " << utc << std::endl;
// get time string gregorian calendar
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;
LOG(INFO) << "Galileo RX time at " << boost::posix_time::to_simple_string(p_time);
//end debug
// SV ECEF DEBUG OUTPUT
DLOG(INFO) << "ECEF satellite SV ID=" << galileo_ephemeris_iter->second.i_satellite_PRN
<< " X=" << galileo_ephemeris_iter->second.d_satpos_X
<< " [m] Y=" << galileo_ephemeris_iter->second.d_satpos_Y
<< " [m] Z=" << galileo_ephemeris_iter->second.d_satpos_Z
<< " [m] PR_obs=" << obs(obs_counter) << " [m]";
}
else // the ephemeris are not available for this SV
{
// no valid pseudorange for the current SV
W(obs_counter, obs_counter) = 0; // SV de-activated
obs(obs_counter) = 1; // to avoid algorithm problems (divide by zero)
DLOG(INFO) << "No ephemeris data for SV " << gnss_pseudoranges_iter->first;
}
}
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
gps_ephemeris_iter = gps_ephemeris_map.find(gnss_pseudoranges_iter->first);
if (gps_ephemeris_iter != gps_ephemeris_map.end())
{
/*!
* \todo Place here the satellite CN0 (power level, or weight factor)
*/
W(obs_counter, obs_counter) = 1;
// 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;
// 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);
// 3- compute the current ECEF position for this SV using corrected TX time
TX_time_corrected_s = Tx_time - SV_clock_bias_s;
gps_ephemeris_iter->second.satellitePosition(TX_time_corrected_s);
satpos(0, obs_counter) = gps_ephemeris_iter->second.d_satpos_X;
satpos(1, obs_counter) = gps_ephemeris_iter->second.d_satpos_Y;
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;
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++;
valid_obs_GPS_counter++;
// SV ECEF DEBUG OUTPUT
DLOG(INFO) << "(new)ECEF satellite SV ID=" << gps_ephemeris_iter->second.i_satellite_PRN
<< " X=" << gps_ephemeris_iter->second.d_satpos_X
<< " [m] Y=" << gps_ephemeris_iter->second.d_satpos_Y
<< " [m] Z=" << gps_ephemeris_iter->second.d_satpos_Z
<< " [m] PR_obs=" << obs(obs_counter) << " [m]";
// compute the UTC time for this SV (just to print the asociated UTC timestamp)
GPS_week = gps_ephemeris_iter->second.i_GPS_week;
utc = gps_utc_model.utc_time(TX_time_corrected_s, GPS_week);
}
else // the ephemeris are not available for this SV
{
// no valid pseudorange for the current SV
W(obs_counter, obs_counter) = 0; // SV de-activated
obs(obs_counter) = 1; // to avoid algorithm problems (divide by zero)
DLOG(INFO) << "No ephemeris data for SV " << gnss_pseudoranges_iter->first;
}
}
obs_counter++;
}
// ********************************************************************************
// ****** SOLVE LEAST SQUARES******************************************************
// ********************************************************************************
d_valid_observations = valid_obs;
d_valid_GPS_obs = valid_obs_GPS_counter;
d_valid_GAL_obs = valid_obs_GALILEO_counter;
LOG(INFO) << "HYBRID PVT: valid observations=" << valid_obs;
if (valid_obs >= 4)
{
arma::vec mypos;
DLOG(INFO) << "satpos=" << satpos;
DLOG(INFO) << "obs="<< obs;
DLOG(INFO) << "W=" << W;
mypos = hybrid_ls_pvt::leastSquarePos(satpos, obs, W);
// Compute GST and Gregorian time
double GST = galileo_ephemeris_map.find(gnss_pseudoranges_iter->first)->second.Galileo_System_Time(Galileo_week_number, hybrid_current_time);
utc = galileo_utc_model.GST_to_UTC_time(GST, Galileo_week_number);
// get time string Gregorian calendar
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;
hybrid_ls_pvt::cart2geo(static_cast<double>(mypos(0)), static_cast<double>(mypos(1)), static_cast<double>(mypos(2)), 4);
//ToDo: Find an Observables/PVT random bug with some satellite configurations that gives an erratic PVT solution (i.e. height>50 km)
if (d_height_m > 50000)
{
b_valid_position = false;
LOG(INFO) << "Hybrid Position at " << boost::posix_time::to_simple_string(p_time)
<< " is Lat = " << d_latitude_d << " [deg], Long = " << d_longitude_d
<< " [deg], Height= " << d_height_m << " [m]";
//std::cout << "Hybrid Position at " << boost::posix_time::to_simple_string(p_time)
// << " is Lat = " << d_latitude_d << " [deg], Long = " << d_longitude_d
// << " [deg], Height= " << d_height_m << " [m]" << std::endl;
return false;
}
LOG(INFO) << "Hybrid Position at " << boost::posix_time::to_simple_string(p_time)
<< " is Lat = " << d_latitude_d << " [deg], Long = " << d_longitude_d
<< " [deg], Height= " << d_height_m << " [m]";
// ###### Compute DOPs ########
hybrid_ls_pvt::compute_DOP();
// ######## LOG FILE #########
if(d_flag_dump_enabled == true)
{
// MULTIPLEXED FILE RECORDING - Record results to file
try
{
double tmp_double;
// PVT GPS time
tmp_double = hybrid_current_time;
d_dump_file.write((char*)&tmp_double, sizeof(double));
// ECEF User Position East [m]
tmp_double = mypos(0);
d_dump_file.write((char*)&tmp_double, sizeof(double));
// ECEF User Position North [m]
tmp_double = mypos(1);
d_dump_file.write((char*)&tmp_double, sizeof(double));
// ECEF User Position Up [m]
tmp_double = mypos(2);
d_dump_file.write((char*)&tmp_double, sizeof(double));
// User clock offset [s]
tmp_double = mypos(3);
d_dump_file.write((char*)&tmp_double, sizeof(double));
// GEO user position Latitude [deg]
tmp_double = d_latitude_d;
d_dump_file.write((char*)&tmp_double, sizeof(double));
// GEO user position Longitude [deg]
tmp_double = d_longitude_d;
d_dump_file.write((char*)&tmp_double, sizeof(double));
// GEO user position Height [m]
tmp_double = d_height_m;
d_dump_file.write((char*)&tmp_double, sizeof(double));
}
catch (const std::ifstream::failure& e)
{
LOG(WARNING) << "Exception writing PVT LS dump file "<< e.what();
}
}
// MOVING AVERAGE PVT
hybrid_ls_pvt::pos_averaging(flag_averaging);
}
else
{
b_valid_position = false;
}
return b_valid_position;
}