gnss-sdr/src/core/system_parameters/gps_navigation_message.h

258 lines
12 KiB
C++

/*!
* \file gps_navigation_message.h
* \brief Interface of a GPS NAV Data message decoder
* \author Javier Arribas, 2011. jarribas(at)cttc.es
*
*
* -----------------------------------------------------------------------------
*
* Copyright (C) 2010-2020 (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.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_GPS_NAVIGATION_MESSAGE_H
#define GNSS_SDR_GPS_NAVIGATION_MESSAGE_H
#include "GPS_L1_CA.h"
#include "gps_ephemeris.h"
#include "gps_iono.h"
#include "gps_utc_model.h"
#include <bitset>
#include <cstdint>
#include <map>
#include <string>
#include <utility> // for pair
#include <vector>
/*!
* \brief This class decodes a GPS NAV Data message as described in IS-GPS-200K
*
* See https://www.gps.gov/technical/icwg/IS-GPS-200K.pdf Appendix II
*/
class Gps_Navigation_Message
{
public:
/*!
* Default constructor
*/
Gps_Navigation_Message();
/*!
* \brief Obtain a GPS SV Ephemeris class filled with current SV data
*/
Gps_Ephemeris get_ephemeris() const;
/*!
* \brief Obtain a GPS ionospheric correction parameters class filled with current SV data
*/
Gps_Iono get_iono();
/*!
* \brief Obtain a GPS UTC model parameters class filled with current SV data
*/
Gps_Utc_Model get_utc_model();
/*!
* \brief Decodes the GPS NAV message
*/
int32_t subframe_decoder(char* subframe);
/*!
* \brief Computes the Coordinated Universal Time (UTC) and
* returns it in [s] (IS-GPS-200K, 20.3.3.5.2.4)
*/
double utc_time(const double gpstime_corrected) const;
/*!
* \brief Gets Time of Week, in seconds
*/
inline int32_t get_TOW() const
{
return d_TOW;
}
/*!
* \brief Sets Time of Week, in seconds
*/
inline int32_t get_GPS_week() const
{
return i_GPS_week;
}
/*!
* \brief Sets satellite PRN number
*/
inline void set_satellite_PRN(uint32_t prn)
{
i_satellite_PRN = prn;
}
/*!
* \brief Gets satellite PRN number
*/
inline uint32_t get_satellite_PRN() const
{
return i_satellite_PRN;
}
/*!
* \brief Sets channel ID
*/
inline void set_channel(int32_t channel_id)
{
i_channel_ID = channel_id;
}
/*!
* \brief Gets flag_iono_valid
*/
inline bool get_flag_iono_valid() const
{
return flag_iono_valid;
}
/*!
* \brief Gets flag_utc_model_valid
*/
inline bool get_flag_utc_model_valid() const
{
return flag_utc_model_valid;
}
bool satellite_validation();
private:
uint64_t read_navigation_unsigned(std::bitset<GPS_SUBFRAME_BITS> bits, const std::vector<std::pair<int32_t, int32_t>>& parameter) const;
int64_t read_navigation_signed(std::bitset<GPS_SUBFRAME_BITS> bits, const std::vector<std::pair<int32_t, int32_t>>& parameter) const;
bool read_navigation_bool(std::bitset<GPS_SUBFRAME_BITS> bits, const std::vector<std::pair<int32_t, int32_t>>& parameter) const;
void print_gps_word_bytes(uint32_t GPS_word) const;
std::map<int32_t, int32_t> almanacHealth; //!< Map that stores the health information stored in the almanac
std::map<int32_t, std::string> satelliteBlock; //!< Map that stores to which block the PRN belongs https://www.navcen.uscg.gov/?Do=constellationStatus
// broadcast orbit 1
int32_t d_TOW{}; // Time of GPS Week of the ephemeris set (taken from subframes TOW) [s]
int32_t d_TOW_SF1{}; // Time of GPS Week from HOW word of Subframe 1 [s]
int32_t d_TOW_SF2{}; // Time of GPS Week from HOW word of Subframe 2 [s]
int32_t d_TOW_SF3{}; // Time of GPS Week from HOW word of Subframe 3 [s]
int32_t d_TOW_SF4{}; // Time of GPS Week from HOW word of Subframe 4 [s]
int32_t d_TOW_SF5{}; // Time of GPS Week from HOW word of Subframe 5 [s]
int32_t d_IODE_SF2{};
int32_t d_IODE_SF3{};
double d_Crs{}; // Amplitude of the Sine Harmonic Correction Term to the Orbit Radius [m]
double d_Delta_n{}; // Mean Motion Difference From Computed Value [semi-circles/s]
double d_M_0{}; // Mean Anomaly at Reference Time [semi-circles]
// broadcast orbit 2
double d_Cuc{}; // Amplitude of the Cosine Harmonic Correction Term to the Argument of Latitude [rad]
double d_e_eccentricity{}; // Eccentricity [dimensionless]
double d_Cus{}; // Amplitude of the Sine Harmonic Correction Term to the Argument of Latitude [rad]
double d_sqrt_A{}; // Square Root of the Semi-Major Axis [sqrt(m)]
// broadcast orbit 3
int32_t d_Toe{}; // Ephemeris data reference time of week (Ref. 20.3.3.4.3 IS-GPS-200K) [s]
int32_t d_Toc{}; // clock data reference time (Ref. 20.3.3.3.3.1 IS-GPS-200K) [s]
double d_Cic{}; // Amplitude of the Cosine Harmonic Correction Term to the Angle of Inclination [rad]
double d_OMEGA0{}; // Longitude of Ascending Node of Orbit Plane at Weekly Epoch [semi-circles]
double d_Cis{}; // Amplitude of the Sine Harmonic Correction Term to the Angle of Inclination [rad]
// broadcast orbit 4
double d_i_0{}; // Inclination Angle at Reference Time [semi-circles]
double d_Crc{}; // Amplitude of the Cosine Harmonic Correction Term to the Orbit Radius [m]
double d_OMEGA{}; // Argument of Perigee [semi-cicles]
double d_OMEGA_DOT{}; // Rate of Right Ascension [semi-circles/s]
// broadcast orbit 5
double d_IDOT{}; // Rate of Inclination Angle [semi-circles/s]
int32_t i_code_on_L2{}; // If 1, P code ON in L2; if 2, C/A code ON in L2;
int32_t i_GPS_week{}; // GPS week number, aka WN [week]
bool b_L2_P_data_flag{}; // When true, indicates that the NAV data stream was commanded OFF on the P-code of the L2 channel
// broadcast orbit 6
int32_t i_SV_accuracy{}; // User Range Accuracy (URA) index of the SV (reference paragraph 6.2.1) for the standard positioning service user (Ref 20.3.3.3.1.3 IS-GPS-200K)
int32_t i_SV_health{};
double d_TGD{}; // Estimated Group Delay Differential: L1-L2 correction term only for the benefit of "L1 P(Y)" or "L2 P(Y)" s users [s]
int32_t d_IODC{}; // Issue of Data, Clock
// broadcast orbit 7
int32_t i_AODO{}; // Age of Data Offset (AODO) term for the navigation message correction table (NMCT) contained in subframe 4 (reference paragraph 20.3.3.5.1.9) [s]
bool b_fit_interval_flag{}; // indicates the curve-fit interval used by the CS (Block II/IIA/IIR/IIR-M/IIF) and SS (Block IIIA) in determining the ephemeris parameters, as follows: 0 = 4 hours, 1 = greater than 4 hours.
double d_spare1{};
double d_spare2{};
double d_A_f0{}; // Coefficient 0 of code phase offset model [s]
double d_A_f1{}; // Coefficient 1 of code phase offset model [s/s]
double d_A_f2{}; // Coefficient 2 of code phase offset model [s/s^2]
// Almanac
int32_t i_Toa{}; // Almanac reference time [s]
int32_t i_WN_A{}; // Modulo 256 of the GPS week number to which the almanac reference time (i_Toa) is referenced
// clock terms
// double d_master_clock{}; // GPS transmission time
double d_dtr{}; // relativistic clock correction term
double d_satClkDrift{};
// satellite positions
double d_satpos_X{}; // Earth-fixed coordinate x of the satellite [m]. Intersection of the IERS Reference Meridian (IRM) and the plane passing through the origin and normal to the Z-axis.
double d_satpos_Y{}; // Earth-fixed coordinate y of the satellite [m]. Completes a right-handed, Earth-Centered, Earth-Fixed orthogonal coordinate system.
double d_satpos_Z{}; // Earth-fixed coordinate z of the satellite [m]. The direction of the IERS (International Earth Rotation and Reference Systems Service) Reference Pole (IRP).
// Satellite velocity
double d_satvel_X{}; // Earth-fixed velocity coordinate x of the satellite [m]
double d_satvel_Y{}; // Earth-fixed velocity coordinate y of the satellite [m]
double d_satvel_Z{}; // Earth-fixed velocity coordinate z of the satellite [m]
// satellite identification info
int32_t i_channel_ID{};
uint32_t i_satellite_PRN{};
// Ionospheric parameters
double d_alpha0{}; // Coefficient 0 of a cubic equation representing the amplitude of the vertical delay [s]
double d_alpha1{}; // Coefficient 1 of a cubic equation representing the amplitude of the vertical delay [s/semi-circle]
double d_alpha2{}; // Coefficient 2 of a cubic equation representing the amplitude of the vertical delay [s(semi-circle)^2]
double d_alpha3{}; // Coefficient 3 of a cubic equation representing the amplitude of the vertical delay [s(semi-circle)^3]
double d_beta0{}; // Coefficient 0 of a cubic equation representing the period of the model [s]
double d_beta1{}; // Coefficient 1 of a cubic equation representing the period of the model [s/semi-circle]
double d_beta2{}; // Coefficient 2 of a cubic equation representing the period of the model [s(semi-circle)^2]
double d_beta3{}; // Coefficient 3 of a cubic equation representing the period of the model [s(semi-circle)^3]
// UTC parameters
double d_A0{}; // Constant of a model that relates GPS and UTC time (ref. 20.3.3.5.2.4 IS-GPS-200K) [s]
double d_A1{}; // 1st order term of a model that relates GPS and UTC time (ref. 20.3.3.5.2.4 IS-GPS-200K) [s/s]
int32_t d_t_OT{}; // Reference time for UTC data (reference 20.3.4.5 and 20.3.3.5.2.4 IS-GPS-200K) [s]
int32_t i_WN_T{}; // UTC reference week number [weeks]
int32_t d_DeltaT_LS{}; // delta time due to leap seconds [s]. Number of leap seconds since 6-Jan-1980 as transmitted by the GPS almanac.
int32_t i_WN_LSF{}; // Week number at the end of which the leap second becomes effective [weeks]
int32_t i_DN{}; // Day number (DN) at the end of which the leap second becomes effective [days]
int32_t d_DeltaT_LSF{}; // Scheduled future or recent past (relative to NAV message upload) value of the delta time due to leap seconds [s]
// Flags
bool b_valid_ephemeris_set_flag{}; // flag indicating that this ephemeris set have passed the validation check
bool flag_iono_valid{}; // If set, it indicates that the ionospheric parameters are filled (page 18 has arrived and decoded)
bool flag_utc_model_valid{}; // If set, it indicates that the UTC model parameters are filled
/* If true, enhanced level of integrity assurance.
*
* If false, indicates that the conveying signal is provided with the legacy level of integrity assurance.
* That is, the probability that the instantaneous URE of the conveying signal exceeds 4.42 times the upper bound
* value of the current broadcast URA index, for more than 5.2 seconds, without an accompanying alert, is less
* than 1E-5 per hour. If true, indicates that the conveying signal is provided with an enhanced level of
* integrity assurance. That is, the probability that the instantaneous URE of the conveying signal exceeds 5.73
* times the upper bound value of the current broadcast URA index, for more than 5.2 seconds, without an
* accompanying alert, is less than 1E-8 per hour.
*/
bool b_integrity_status_flag{};
bool b_alert_flag{}; // If true, indicates that the SV URA may be worse than indicated in d_SV_accuracy, use that SV at our own risk.
bool b_antispoofing_flag{}; // If true, the AntiSpoofing mode is ON in that SV
};
#endif