/// <summary>
/// 空间直角坐标系到，站心坐标系的转换。默认B L 单位 度，可以为球坐标和大地坐标
/// 地心空间直角坐标系(XYZ)转换为地方左手笛卡尔直角坐标系（NEU,XYZ）
/// </summary>
/// <param name="vector1">测站到卫星的向径</param>
/// <param name="lat">站点所在纬度</param>
/// <param name="lon">站点所在经度</param>
/// <param name="angleUnit">站点所在经度的单位</param>
/// <returns></returns>
public static NEU XyzToNeu(XYZ vector1, double lat, double lon, AngleUnit angleUnit = AngleUnit.Degree)
{
if (angleUnit != AngleUnit.Radian) //当前经度为 0 的时候，U 的转换会出现符号错误？？？！！！2017.10.12.
{
lat = AngularConvert.ToRad(lat, angleUnit);
lon = AngularConvert.ToRad(lon, angleUnit);
}
XYZ v = vector1;
double n = -v.X * Sin(lat) * Cos(lon) - v.Y * Sin(lat) * Sin(lon) + v.Z * Cos(lat);
double e = -v.X * Sin(lon) + v.Y * Cos(lon);
double u = v.X * Cos(lat) * Cos(lon) + v.Y * Cos(lat) * Sin(lon) + v.Z * Sin(lat);
return(new NEU(n, e, u));// { N = n, E = e, U = u };
}
/// <summary>
/// 椭球坐标转为空间直角坐标。默认单位为度。
/// </summary>
/// <param name="lon">经度（度）</param>
/// <param name="lat">纬度（度）</param>
/// <param name="height">大地高</param>
/// <param name="a">椭球半径</param>
/// <param name="flatOrInverse">扁率或其倒数</param>
/// <param name="unit">单位</param>
/// <returns></returns>
public static XYZ GeoCoordToXyz(double lon, double lat, double height, double a, double flatOrInverse, AngleUnit unit = AngleUnit.Degree)
{
lon = AngularConvert.ToRad(lon, unit);
lat = AngularConvert.ToRad(lat, unit);
//扁率判断
double e = flatOrInverse;
if (flatOrInverse > 1)
{
e = 1.0 / e;
}
double n = a / Math.Sqrt(1 - Math.Pow(e * Sin(lat), 2));
double x = (n + height) * Cos(lat) * Cos(lon);
double y = (n + height) * Cos(lat) * Sin(lon);
double z = (n * (1 - e * e) + height) * Sin(lat);
return(new XYZ(x, y, z));
}
