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

104 lines
3.4 KiB
C++

/*!
* \file gnss_almanac.h
* \brief Base class for GNSS almanac storage
* \author Carles Fernandez, 2021. cfernandez(at)cttc.es
*
* -----------------------------------------------------------------------------
*
* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
* This file is part of GNSS-SDR.
*
* Copyright (C) 2010-2021 (see AUTHORS file for a list of contributors)
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_GNSS_ALMANAC_H
#define GNSS_SDR_GNSS_ALMANAC_H
#include <array>
#include <cstdint>
/** \addtogroup Core
* \{ */
/** \addtogroup System_Parameters
* \{ */
/*!
* \brief Base class for GNSS almanac storage
*/
class Gnss_Almanac
{
public:
/*!
* Default constructor
*/
Gnss_Almanac() = default;
/*!
* \brief Computes prediction of the Doppler shift for a given time and receiver's position and velocity.
* \f[
* f_{d} = - \mathbf{v} \frac{\mathbf{x}^{T}}{\left| \mathbf{x} \right| } \frac{f_{L}}{c}
* \f]
* where:
* \f[
* \mathbf{v} = \mathbf{v}_{sat} - \mathbf{v}_{rx}
* \f]
* \f[
* \mathbf{x} = \mathbf{x}_{sat} - \mathbf{x}_{rx}
* \f]
* \f[
* \left| \mathbf{x} \right| = \sqrt{\mathbf{x}\mathbf{x}^{T}}
* \f]
*
* @param[in] rx_time_s Time of Week in seconds
* @param[in] lat Receiver's latitude in degrees
* @param[in] lon Receiver's longitude in degrees
* @param[in] h Receiver's height in meters
* @param[in] ve Receiver's velocity in the East direction [m/s]
* @param[in] vn Receiver's velocity in the North direction [m/s]
* @param[in] vu Receiver's velocity in the Up direction [m/s]
* @param[in] band Signal band for which the Doppler will be computed
* (1: L1 C/A, E1B, BI1; 2: L2C, BI2; 3: BI3; 5: L5/E5a; 6: E6B; 7: E5b; 8: E5a+E5b)
*/
double predicted_doppler(double rx_time_s,
double lat,
double lon,
double h,
double ve,
double vn,
double vu,
int band) const;
/*!
* \brief Computes satellite Position and Velocity, in ECEF, for a given time (expressed in seconds of week)
*/
void satellitePosVelComputation(double transmitTime, std::array<double, 7>& pos_vel_dtr) const;
uint32_t PRN{}; //!< SV PRN NUMBER
double delta_i{}; //!< Inclination Angle at Reference Time (relative to i_0 = 0.30 semi-circles)
int32_t toa{}; //!< Almanac data reference time of week [s]
int32_t WNa{}; //!< Almanac week number
double M_0{}; //!< Mean Anomaly at Reference Time [semi-circles]
double ecc{}; //!< Eccentricity [dimensionless]
double sqrtA{}; //!< Square Root of the Semi-Major Axis [sqrt(m)]
double OMEGA_0{}; //!< Longitude of Ascending Node of Orbit Plane at Weekly Epoch [semi-circles]
double omega{}; //!< Argument of Perigee [semi-cicles]
double OMEGAdot{}; //!< Rate of Right Ascension [semi-circles/s]
double af0{}; //!< Coefficient 0 of code phase offset model [s]
double af1{}; //!< Coefficient 1 of code phase offset model [s/s]
protected:
char System{}; //!< Character ID of the GNSS system. 'G': GPS. 'E': Galileo. 'B': BeiDou
private:
double check_t(double time) const;
};
/** \} */
/** \} */
#endif // GNSS_SDR_GNSS_ALMANAC_H