calc_error.c

根据GPS官方网站提供的gps定位方法而编写的C语言gps定位代码

#include <math.h>
#include "gps.h"
/*
 *      Allows approximate calculation of ground distance
 *	from known latitude and longitude - the values
 *	MY_LAT and MY_LON in gps.h
 */
calc_error(double lat, double lon , double height) /* these are in degrees */
{
	double dx = ( MY_LAT - lat) * 111225.0;
	double dy = ( MY_LON - lon) * 68875.0;
	double error = sqrt( dx * dx + dy * dy);
	printf("Pos error = %f\n",error);
}