我正在开发一个地理空间AR应用程序，并且刚刚在Objective-C/iOS(来自Apple的this example code提供了相当多的帮助)中解决了这个问题。

将从lat lon转换为ecef到ENU并返回的三个C函数如下所示。数学公式来自this维基百科的文章。

#define RADIANS_TO_DEGREES(radians) ((radians) * (180.0/M_PI))

#define DEGREES_TO_RADIANS(degrees)((M_PI * degrees)/180)

#define WGS84_A (6378137.0) // WGS 84 semi-major axis constant in meters

#define WGS84_E (8.1819190842622e-2) // WGS 84 eccentricity

// Converts latitude, longitude to ECEF coordinate system

void latLonToEcef(double lat, double lon, double alt, double *x, double *y, double *z)

{

double clat = cos(DEGREES_TO_RADIANS(lat));

double slat = sin(DEGREES_TO_RADIANS(lat));

double clon = cos(DEGREES_TO_RADIANS(lon));

double slon = sin(DEGREES_TO_RADIANS(lon));

double N = WGS84_A/sqrt(1.0 - WGS84_E * WGS84_E * slat * slat);

*x = (N + alt) * clat * clon;

*y = (N + alt) * clat * slon;

*z = (N * (1.0 - WGS84_E * WGS84_E) + alt) * slat;

}

// Converts ECEF to ENU coordinates centered at given lat, lon

void ecefToEnu(double lat, double lon, double xRef, double yRef, double zRef, double xPOI, double yPOI, double zPOI, double *e, double *n, double *u)

{

double clat = cos(DEGREES_TO_RADIANS(lat));

double slat = sin(DEGREES_TO_RADIANS(lat));

double clon = cos(DEGREES_TO_RADIANS(lon));

double slon = sin(DEGREES_TO_RADIANS(lon));

double dx = xPOI - xRef;

double dy = yPOI - yRef;

double dz = zPOI - zRef;

*e = -slon * dx + clon * dy;

*n = -slat * clon * dx - slat * slon * dy + clat * dz;

*u = clat * clon * dx + clat * slon * dy + slat * dz;

}

// Converts ENU of a POI (in realtion to a reference point) to ECEF coordinates

void enuToEcef(double lat, double lon, double xRef, double yRef, double zRef, double *xPOI, double *yPOI, double *zPOI, double e, double n, double u)

{

double clat = cos(DEGREES_TO_RADIANS(lat));

double slat = sin(DEGREES_TO_RADIANS(lat));

double clon = cos(DEGREES_TO_RADIANS(lon));

double slon = sin(DEGREES_TO_RADIANS(lon));

*xPOI = (-slon * e) + (-slat * clon * n) + (clat * clon * u) + xRef;

*yPOI = (clon * e) + (-slat * slon * n) + (clat * slon * u) + yRef;

*zPOI = (0 * e) + (clat * n) + (slat * u) + zRef;

}