mirror of https://github.com/gnss-sdr/gnss-sdr
75 lines
3.5 KiB
C++
75 lines
3.5 KiB
C++
/*
|
|
* \file galileo_utc_model.h
|
|
* \brief Interface of a Galileo UTC MODEL storage
|
|
* \author Javier Arribas, 2013. jarribas(at)cttc.es
|
|
*
|
|
* -----------------------------------------------------------------------------
|
|
*
|
|
* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
|
|
* This file is part of GNSS-SDR.
|
|
*
|
|
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
|
|
* SPDX-License-Identifier: GPL-3.0-or-later
|
|
*
|
|
* -----------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include "galileo_utc_model.h"
|
|
#include <cmath>
|
|
|
|
|
|
double Galileo_Utc_Model::GST_to_UTC_time(double t_e, int32_t WN) const
|
|
{
|
|
double t_Utc;
|
|
double t_Utc_daytime;
|
|
double Delta_t_Utc = 0;
|
|
// Determine if the effectivity time of the leap second event is in the past
|
|
const int32_t weeksToLeapSecondEvent = WN_LSF - (WN % 256);
|
|
|
|
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
|
|
const int secondOfLeapSecondEvent = DN * 24 * 60 * 60;
|
|
if (std::abs(t_e - secondOfLeapSecondEvent) > 21600)
|
|
{
|
|
/* 5.1.7a GST->UTC case a
|
|
* Whenever the leap second adjusted 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 effective time and ends at six hours after the effective time,
|
|
* the GST/Utc relationship is given by
|
|
*/
|
|
Delta_t_Utc = Delta_tLS + A0 + A1 * (t_e - tot + 604800 * static_cast<double>((WN % 256) - WNot));
|
|
t_Utc_daytime = fmod(t_e - Delta_t_Utc, 86400);
|
|
}
|
|
else
|
|
{
|
|
/* 5.1.7b GST->UTC case b
|
|
* Whenever the user's current time falls within the time span of six hours
|
|
* prior to the leap second adjustment to six hours after the adjustment time,
|
|
* the effective time is computed according to the following equations:
|
|
*/
|
|
Delta_t_Utc = Delta_tLS + A0 + A1 * (t_e - tot + 604800 * static_cast<double>((WN % 256) - WNot));
|
|
const double W = fmod(t_e - Delta_t_Utc - 43200, 86400) + 43200;
|
|
t_Utc_daytime = fmod(W, 86400 + Delta_tLSF - Delta_tLS);
|
|
// implement something to handle a leap second event!
|
|
}
|
|
}
|
|
else // the effectivity time is in the past
|
|
{
|
|
/* 5.1.7c GST->UTC case c
|
|
* Whenever the leap second adjustment time, as indicated by the WN_LSF and DN values,
|
|
* is in the past (relative to the user's current time) and the user's present time does not
|
|
* fall in the time span which starts six hours prior to the leap second adjustment time and
|
|
* ends six hours after the adjustment time, the effective time is computed according to
|
|
* the following equation:
|
|
*/
|
|
Delta_t_Utc = Delta_tLSF + A0 + A1 * (t_e - tot + 604800 * static_cast<double>((WN % 256) - WNot));
|
|
t_Utc_daytime = fmod(t_e - Delta_t_Utc, 86400);
|
|
}
|
|
|
|
const double secondsOfWeekBeforeToday = 86400 * floor(t_e / 86400);
|
|
t_Utc = secondsOfWeekBeforeToday + t_Utc_daytime;
|
|
return t_Utc;
|
|
}
|