gregorian_to_julian.c

最大似然估计算法

#include "utc_time.h"

double gregorian_to_julian(year,month,day,hour,minute,second)
int year, month, day, hour, minute;
double second;
{
	int a, jd;

	double total, decimal_day;
	
	a = (month - 14) / 12;
	jd = (1461 * (year + 4800 + a ) ) / 4;
	jd += (367*(month- 2 - 12 * a)) / 12;
	jd -= (3 * (year+4900+a)/100) / 4;
	jd += day;

	decimal_day =  (double)hour / 24.0;
	decimal_day += (double)minute / 1440.0;
	decimal_day += (double)second / 86400.0;

	total = (double)jd - 32075.5 + decimal_day;
	return(total);
}