Program Listing for File gnss_measurement.h¶
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#pragma once
#include <memory>
#include <vector>
#include "lupnt/core/constants.h"
#include "lupnt/measurements/transmission.h"
#include "lupnt/physics/frame_converter.h"
namespace lupnt {
enum GnssMeasurementType {
PR, // Pseudorange
PRR, // Pseudorange rate
CP, // Carrier phase
};
class GnssMeasurement {
// Implemenation based on Gnss SDR Observables block:
// https://gnss-sdr.org/docs/sp-blocks/observables/
private:
int n_meas = 0; // Number of measurements
std::vector<GnssTransmission> trans_store; // list of transmittion data
std::vector<int> ID_tx; // ID of the transmitter (n_meas)
// Visbility
VecXd vis_earth;
VecXd vis_moon;
VecXd vis_antenna;
VecXd vis_atmos;
VecXd vis_ionos;
double c = 299792.458; // Speed of light [km/s]
// Pseudorange measurement
double t_rx; // Signal reception time measured by the receiver clock [s]
double t_tx; // Signal transmission time measured by the transmitter clock [s]
VecX P_rx; // Pseudorange measurement [km] (n_meas * n_bands)
VecXd rho_rx; // True range from the transmitter to the receiver’s
// antenna [km] (n_meas)
double dt_rx; // Receiver clock offset from Gnss time [s]
VecXd dt_tx; // Transmitter clock offset from Gnss time [s] (n_meas)
VecXd I_rx; // Ionospheric delay [km] (n_meas * n_bands)
VecXd T_rx; // Tropospheric delay [km] (n_meas)
VecXd eps_P; // Pseudorange measurement noise [km] (n_meas)
// Carrier phase measurement
VecX phi_rx; // Carrier phase measurement [cycles] (n_meas * n_bands)
VecXd phi_rx_tx; // Phase of the receiver's local oscillator at
// time t [cycles] (n_meas * n_bands)
VecXd phi_tx; // Phase of the transmitted signal at time t [cycles]
// (n_meas * n_bands)
double t;
VecXd N_rx; // Carrier phase int ambiguity [cycles] (n_meas * n_bands)
VecXd eps_phi; // Carrier phase measurement noise [cycles]
// (n_meas * n_bands)
VecXd f; // Carrier frequency [Hz] (n_bands) // TODO: Convert to vector
double t_0; // Initial time [s]
VecXd phi_0; // Initial phase of the transmitted signal at time t_0
// [cycles] (n_meas * n_bands)
VecXd lambda_; // Carrier wavelength [km] (n_bands) // TODO: Convert to vector
VecXd L_rx_txr; // Integer component of the receiver’s numerically
// controlled oscillator (NCO) phase
VecXd K_rx_txr; // Integer component of the propagation term
// Phase-range masurement
VecXd Phi_rx; // Phase-range measurement [km] (n_meas * n_bands)
// (n_meas * n_bands)
VecXd B_rx; // Carrier phase bias [cycles] (n_meas * n_bands)
VecXd dPhi_rx; // Receiver’s antenna phase center variation [km]
// (n_meas * n_bands)
VecXd d_rx_pco; // Receiver’s antenna phase center offset in local
// coordinates [km] (n_meas) (n_bands x 3)
VecXd d_rx_pcv; // Receiver’s antenna phase center variation [km]
// (n_meas * n_bands)
VecXd d_tx_pco; // Transmitter’s antenna phase center offset in
// local coordinates [km] (n_meas * n_bands x 3)
VecXd d_tx_pcv; // Transmitter’s antenna phase center variation
// [km] (n_meas * n_bands)
MatXd e_rx_enu; // LOS vector from receiver antenna to satellite in
// local coordinates [km] (n_meas x 3)
MatXd e_rx; // LOS vector from receiver antenna to satellite in
// ECEF coordinates [km] (n_meas x 3)
VecXd E; // Coordinates transformation matrix from the satellite
// body‐fixed coordinates to ECEF coordinates
Vec3d d_rx_disp; // Displacement by Earth tides at the receiver
// position in local coordinates [km] (3)
VecXd eps_Phi; // Phase-range measurement noise [km] (n_bands)
// Doppler shift measurement
VecXd D_rx; // Doppler shift measurement [Hz] (n_meas * n_bands)
VecX r_rx; // Position of the receiver at time t_rx [km] (3)
MatXd r_tx; // Position of the transmitter at time t_rx [km] (n_meas x 3)
VecXd v_rx; // Velocity of the receiver at time t_rx [m/s] (3)
MatXd v_tx; // Velocity of the transmitter at time t_tx [m/s] (n_meas x 3)
VecXd eps_D; // Doppler shift measurement noise [Hz] (n_meas * n_bands)
// Pseudorange rate measurement
VecXd PR_rx; // Pseudorange rate measurement [m/s] (n_meas * n_bands)
double dt_rx_dot; // Receiver clock drift [s/s]
VecXd dt_tx_dot; // Transmitter clock drift [s/s] (n_meas)
VecXd eps_PR; // Pseudorange rate measurement noise [m/s]
// (n_meas * n_bands)
// Receiver param
GnssReceiverParam gnssr_param;
double chip_rate; // Chip rate [Hz]
// Link budget
VecXd CN0; // Carrier‐to‐noise density [dB‐Hz] (n_meas * n_bands)
public:
GnssMeasurement(const std::vector<GnssTransmission> transmissions);
GnssMeasurement ExtractSignal(std::string freq_label);
// Transmission data
int GetTrackedSatelliteNum() const { return n_meas; }
std::vector<int> GetTxIds() const { return ID_tx; }
VecX GetCN0() const { return CN0; }
VecXd GetEarthOccultation() const { return vis_earth; }
VecXd GetMoonOccultation() const { return vis_moon; }
VecXd GetAntennaOccultation() const { return vis_antenna; }
VecXd GetIonosOccultation() const { return vis_ionos; }
VecXd GetAtmosOccultation() const { return vis_atmos; }
/***********************************************************
* General Methods for computing Measurements
***********************************************************/
VecX ComputeGnssPseudorange(VecX r_rx, Real dt_rx, bool with_noise = false, int seed = 0);
VecX ComputeGnssPseudorangerate(VecX r_rx, VecX v_rx, Real dt_rx_dot, bool with_noise = false,
int seed = 0);
VecX ComputeGnssCarrierPhase(VecX r_rx, Real dt_rx, VecX N_rx, bool with_noise = false,
int seed = 0);
/***********************************************************
* Methods for true measurement generation
***********************************************************/
VecX GetGnssMeasurement(std::vector<GnssMeasurementType> meas_type, bool with_noise = false,
int seed = 0);
VecX GetPseudorange(bool with_noise = false, int seed = 0);
VecX GetPseudorangerate(bool with_noise = false, int seed = 0);
VecX GetCarrierPhase(bool with_noise = false, int seed = 0);
/***********************************************************
* Methods for predicted measurement generation
***********************************************************/
VecX GetPredictedGnssMeasurement(double epoch, Vec6 rv_pred, Vec2 clk_pred, VecX N_pred,
MatXd &H_gnss, std::vector<GnssMeasurementType> meas_type,
Frame frame_in = Frame::MOON_CI);
VecX GetPredictedPseudorange(double epoch, Vec6 rv_pred, Vec2 clk_pred, MatXd &H_pr,
Frame frame_in = Frame::MOON_CI);
VecX GetPredictedPseudorangeAnalyticalJacobian(double epoch, Vec6 rv_pred, Vec2 clk_pred,
MatXd &H_pr, Frame frame_in = Frame::MOON_CI);
VecX GetPredictedPseudorangerate(double epoch, Vec6 rv_pred, Vec2 clk_pred, MatXd &H_prr,
Frame frame_in = Frame::MOON_CI);
VecX GetPredictedCarrierPhase(double epoch, Vec6 rv_pred, Vec2 clk_pred, VecX N_pred,
MatXd &H_cp, Frame frame_in = Frame::MOON_CI);
/*********************************************************************
* Noise Models
********************************************************************/
VecXd GetGnssNoiseStdVec(std::vector<GnssMeasurementType> meas_type);
VecXd GetPseudorangeNoiseStdVec();
VecXd GetPseudorangeRateNoiseStdVec();
VecXd GetCarrierPhaseNoiseStdVec();
void SetGnssReceiverParam(GnssReceiverParam gnssr_param_input) {
gnssr_param = gnssr_param_input;
}
double ComputeGnssPseudorangeNoise(double CN0);
double ComputeGnssPseudorangerateNoise(double CN0, double lambda);
double ComputeGnssCarrierPhaseNoise(double CN0, double lambda);
};
} // namespace lupnt