写一个差分gps的c语言代码

差分GPS的C语言代码如下：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PI 3.14159265358979323846

// 定义结构体存储GPS测量值
typedef struct {
    double lat; // 纬度
    double lon; // 经度
    double alt; // 海拔高度
    double time; // GPS时间
} gps_t;

// 定义结构体存储差分GPS测量值
typedef struct {
    double lat; // 纬度
    double lon; // 经度
    double alt; // 海拔高度
    double time; // GPS时间
    double dx; // 纬度偏差
    double dy; // 经度偏差
    double dz; // 海拔高度偏差
} dgps_t;

// 计算两点之间的距离
double distance(double lat1, double lon1, double lat2, double lon2) {
    double dlat, dlon, a, c, d;
    dlat = (lat2 - lat1) * PI / 180.0;
    dlon = (lon2 - lon1) * PI / 180.0;
    a = sin(dlat / 2) * sin(dlat / 2) + cos(lat1 * PI / 180.0) * cos(lat2 * PI / 180.0) * sin(dlon / 2) * sin(dlon / 2);
    c = 2 * atan2(sqrt(a), sqrt(1 - a));
    d = 6371000 * c;
    return d;
}

// 计算两个GPS测量值之间的距离
double gps_distance(gps_t gps1, gps_t gps2) {
    return distance(gps1.lat, gps1.lon, gps2.lat, gps2.lon);
}

// 计算两个GPS测量值之间的时间差
double gps_time_diff(gps_t gps1, gps_t gps2) {
    return gps2.time - gps1.time;
}

// 计算两个GPS测量值之间的速度
double gps_speed(gps_t gps1, gps_t gps2) {
    double d = gps_distance(gps1, gps2);
    double t = gps_time_diff(gps1, gps2);
    return d / t;
}

// 计算两个差分GPS测量值之间的距离
double dgps_distance(dgps_t dgps1, dgps_t dgps2) {
    return distance(dgps1.lat, dgps1.lon, dgps2.lat, dgps2.lon);
}

// 计算两个差分GPS测量值之间的时间差
double dgps_time_diff(dgps_t dgps1, dgps_t dgps2) {
    return dgps2.time - dgps1.time;
}

// 计算两个差分GPS测量值之间的速度
double dgps_speed(dgps_t dgps1, dgps_t dgps2) {
    double d = dgps_distance(dgps1, dgps2);
    double t = dgps_time_diff(dgps1, dgps2);
    return d / t;
}

// 计算两个GPS测量值之间的方位角
double gps_bearing(gps_t gps1, gps_t gps2) {
    double lat1 = gps1.lat * PI / 180.0;
    double lon1 = gps1.lon * PI / 180.0;
    double lat2 = gps2.lat * PI / 180.0;
    double lon2 = gps2.lon * PI / 180.0;
    double dlon = lon2 - lon1;
    double y = sin(dlon) * cos(lat2);
    double x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dlon);
    double bearing = atan2(y, x) * 180.0 / PI;
    return bearing;
}

// 计算两个差分GPS测量值之间的方位角
double dgps_bearing(dgps_t dgps1, dgps_t dgps2) {
    return gps_bearing((gps_t){dgps1.lat, dgps1.lon, dgps1.alt, dgps1.time},
                        (gps_t){dgps2.lat, dgps2.lon, dgps2.alt, dgps2.time});
}

// 计算两个GPS测量值之间的高度差
double gps_alt_diff(gps_t gps1, gps_t gps2) {
    return gps2.alt - gps1.alt;
}

// 计算两个差分GPS测量值之间的高度差
double dgps_alt_diff(dgps_t dgps1, dgps_t dgps2) {
    return dgps2.alt - dgps1.alt;
}

// 计算差分GPS的偏差
void compute_dgps_bias(dgps_t *dgps, int n) {
    int i, j, k;
    double dx, dy, dz, dt, v, a;
    for (i = 0; i < n; i++) {
        dx = dy = dz = dt = v = a = 0.0;
        for (j = 0; j < n; j++) {
            if (i != j) {
                double d = dgps_distance(dgps[i], dgps[j]); // 计算两个差分GPS测量值之间的距离
                double t = dgps_time_diff(dgps[i], dgps[j]); // 计算两个差分GPS测量值之间的时间差
                double s = dgps_speed(dgps[i], dgps[j]); // 计算两个差分GPS测量值之间的速度
                double b = dgps_bearing(dgps[i], dgps[j]); // 计算两个差分GPS测量值之间的方位角
                double h = dgps_alt_diff(dgps[i], dgps[j]); // 计算两个差分GPS测量值之间的高度差
                double ex = d * sin(b) / s; // 计算纬度偏差
                double ey = d * cos(b) / s; // 计算经度偏差
                double ez = h; // 计算海拔高度偏差
                double et = t - d / s; // 计算时间偏差
                dx += ex;
                dy += ey;
                dz += ez;
                dt += et;
                v += s;
                a++;
            }
        }
        dgps[i].dx = dx / a;
        dgps[i].dy = dy / a;
        dgps[i].dz = dz / a;
        dgps[i].time += dt / a;
    }
}

int main() {
    int n, i;
    gps_t *gps;
    dgps_t *dgps;
    printf("请输入测量点数：");
    scanf("%d", &n);
    gps = (gps_t*)malloc(sizeof(gps_t) * n);
    dgps = (dgps_t*)malloc(sizeof(dgps_t) * n);
    printf("请输入GPS测量值：\n");
    for (i = 0; i < n; i++) {
        printf("GPS[%d]: ", i+1);
        scanf("%lf %lf %lf %lf", &gps[i].lat, &gps[i].lon, &gps[i].alt, &gps[i].time);
        dgps[i].lat = gps[i].lat;
        dgps[i].lon = gps[i].lon;
        dgps[i].alt = gps[i].alt;
        dgps[i].time = gps[i].time;
    }
    compute_dgps_bias(dgps, n); // 计算差分GPS的偏差
    printf("差分GPS测量值：\n");
    for (i = 0; i < n; i++) {
        printf("DGPS[%d]: %.6f %.6f %.2f %.1f %.4f %.4f %.2f\n", i+1,
            dgps[i].lat, dgps[i].lon, dgps[i].alt, dgps[i].time, dgps[i].dx, dgps[i].dy, dgps[i].dz);
    }
    free(gps);
    free(dgps);
    return 0;
}

该程序通过输入GPS测量值来计算差分GPS测量值，并且计算差分GPS之间的偏差，最后输出差分GPS测量值和偏差。