time.cpp

根据GPS卫星观测文件（.00O）与星历文件(.00N)

#include "time.h"

static int dayInMonth[12] = {31,28,31,30,31,30,31,31,30,31,30,31};

GPSTIME::GPSTIME(GPSTIME& from)
{
	this->iWeek = from.iWeek ;
	this->ldSecond = from.ldSecond ;
}

bool GPSTIME::operator == (GPSTIME& temp)
{
	if(this->iWeek == temp.iWeek  && this->ldSecond == temp.ldSecond )
		return true;
	return false;
}

double GPSTIME::operator - (GPSTIME& temp)
{
	GPSTIME result;
	result.iWeek = this->iWeek - temp.iWeek ;
	result.ldSecond = this->ldSecond - temp.ldSecond ;
	return result.iWeek * 604800 + result.ldSecond  ;
}
double GPSTIME::operator - (const GPSTIME& temp)
{
	GPSTIME result;
	result.iWeek = this->iWeek - temp.iWeek ;
	result.ldSecond = this->ldSecond - temp.ldSecond ;
	return result.iWeek * 604800 + result.ldSecond  ;
}




ATIME::ATIME(const ATIME& from)
{
		wYear = from.wYear;
		byMonth = from.byMonth;
		byDay = from.byDay;
		byHour = from.byHour;
		byMinute = from.byMinute;
		bySecond = from.bySecond;
		byDayOfWeek = from.byDayOfWeek;
}

void ATIME::ConvertToGpsTime(GPSTIME& GpsTime)  //conver ATime to GPS TIME
{
	int year,month,day,hour,minute; 
	long double second,weeksec;

	year=this->wYear ;
	month=this->byMonth ;
	day=this->byDay ;
	hour=this->byHour ;
	minute=this->byMinute ;
	second=this->bySecond ;

	int   dayofw,dayofy, yr, ttlday, m , weekno;

	// Check limits of day, month and year  
	if (year < 1981 || month < 1 || month > 12 || day < 1 || day > 31)
		weekno = 0;
	// Convert day, month and year to day of year 
	if (month == 1)
		dayofy = day;
	else
	{
		dayofy = 0;
		for (m=1; m<=(month-1); m++)
		{
			dayofy += dayInMonth[m];
			if ( m==2 )
			{
				if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
					dayofy += 1;
			}
		}
		dayofy += day;
	}
	//  Convert day of year and year into week number and day of week 
	ttlday = 360;  //GPS系统开始时间1980年1月6日(星期日)0时
	for (yr=1981; yr<=(year-1); yr++)
	{
		ttlday  += 365;
		if ((yr % 4 == 0 && yr % 100 != 0) || (yr % 400 ==0))
			ttlday  += 1;
	}
	ttlday  +=  dayofy;
 	weekno   =  ttlday/7; 
	dayofw   =  ttlday - 7 * weekno;

	weeksec =  (hour * 3600 + minute * 60 + second + dayofw * 86400);//从星期日起算
	GpsTime.iWeek = weekno;
	GpsTime.ldSecond = weeksec;
}

GPSTIME GPSTIME::operator -(const double dSec)
{

	GPSTIME res;
	double t;
	int week;

 	t = this->ldSecond - dSec;
	week = this->iWeek;
	if(t<0) 
	{
		t += 86400;
		week -= 1;
	}
	res.iWeek = week;
	res.ldSecond = t;

	return res;
		
}