mirror of https://github.com/gnss-sdr/gnss-sdr
113 lines
5.0 KiB
C++
113 lines
5.0 KiB
C++
/*
|
|
* \file gps_utc_model.h
|
|
* \brief Interface of a GPS UTC MODEL storage
|
|
* \author Javier Arribas, 2013. jarribas(at)cttc.es
|
|
*
|
|
* -------------------------------------------------------------------------
|
|
*
|
|
* Copyright (C) 2010-2018 (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 <https://www.gnu.org/licenses/>.
|
|
*
|
|
* -------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include "beidou_dnav_utc_model.h"
|
|
|
|
#include <cmath>
|
|
|
|
|
|
Beidou_Utc_Model::Beidou_Utc_Model()
|
|
{
|
|
valid = false;
|
|
d_A1 = 0;
|
|
d_A0 = 0;
|
|
d_t_OT = 0;
|
|
i_WN_T = 0;
|
|
d_DeltaT_LS = 0;
|
|
i_WN_LSF = 0;
|
|
i_DN = 0;
|
|
d_DeltaT_LSF = 0;
|
|
}
|
|
|
|
double Beidou_Utc_Model::utc_time(double beidoutime_corrected, int i_BEIDOU_week)
|
|
{
|
|
double t_utc;
|
|
double t_utc_daytime;
|
|
double Delta_t_UTC = d_DeltaT_LS + d_A0 + d_A1 * (beidoutime_corrected - d_t_OT + 604800 * static_cast<double>(i_BEIDOU_week - i_WN_T));
|
|
|
|
// Determine if the effectivity time of the leap second event is in the past
|
|
int weeksToLeapSecondEvent = i_WN_LSF - i_BEIDOU_week;
|
|
|
|
if (weeksToLeapSecondEvent >= 0) // is not in the past
|
|
{
|
|
//Detect if the effectivity time and user's time is within six hours = 6 * 60 *60 = 21600 s
|
|
int secondOfLeapSecondEvent = i_DN * 24 * 60 * 60;
|
|
if (weeksToLeapSecondEvent > 0)
|
|
{
|
|
t_utc_daytime = fmod(beidoutime_corrected - Delta_t_UTC, 86400);
|
|
}
|
|
else //we are in the same week than the leap second event
|
|
{
|
|
if (std::abs(beidoutime_corrected - secondOfLeapSecondEvent) > 21600)
|
|
{
|
|
/* 20.3.3.5.2.4a
|
|
* Whenever the effectivity time indicated by the WN_LSF and the DN values
|
|
* is not in the past (relative to the user's present time), and the user's
|
|
* present time does not fall in the time span which starts at six hours prior
|
|
* to the effectivity time and ends at six hours after the effectivity time,
|
|
* the UTC/GPS-time relationship is given by
|
|
*/
|
|
t_utc_daytime = fmod(beidoutime_corrected - Delta_t_UTC, 86400);
|
|
}
|
|
else
|
|
{
|
|
/* 20.3.3.5.2.4b
|
|
* Whenever the user's current time falls within the time span of six hours
|
|
* prior to the effectivity time to six hours after the effectivity time,
|
|
* proper accommodation of the leap second event with a possible week number
|
|
* transition is provided by the following expression for UTC:
|
|
*/
|
|
int W = fmod(beidoutime_corrected - Delta_t_UTC - 43200, 86400) + 43200;
|
|
t_utc_daytime = fmod(W, 86400 + d_DeltaT_LSF - d_DeltaT_LS);
|
|
//implement something to handle a leap second event!
|
|
}
|
|
if ((beidoutime_corrected - secondOfLeapSecondEvent) > 21600)
|
|
{
|
|
Delta_t_UTC = d_DeltaT_LSF + d_A0 + d_A1 * (beidoutime_corrected - d_t_OT + 604800 * static_cast<double>(i_BEIDOU_week - i_WN_T));
|
|
t_utc_daytime = fmod(beidoutime_corrected - Delta_t_UTC, 86400);
|
|
}
|
|
}
|
|
}
|
|
else // the effectivity time is in the past
|
|
{
|
|
/* 20.3.3.5.2.4c
|
|
* Whenever the effectivity time of the leap second event, as indicated by the
|
|
* WNLSF and DN values, is in the "past" (relative to the user's current time),
|
|
* and the user's current time does not fall in the time span as given above
|
|
* in 20.3.3.5.2.4b,*/
|
|
Delta_t_UTC = d_DeltaT_LSF + d_A0 + d_A1 * (beidoutime_corrected - d_t_OT + 604800 * static_cast<double>(i_BEIDOU_week - i_WN_T));
|
|
t_utc_daytime = fmod(beidoutime_corrected - Delta_t_UTC, 86400);
|
|
}
|
|
|
|
double secondsOfWeekBeforeToday = 86400 * floor(beidoutime_corrected / 86400);
|
|
t_utc = secondsOfWeekBeforeToday + t_utc_daytime;
|
|
return t_utc;
|
|
}
|