/// <summary>
/// convert geodetic to cartesian (ECEF) coordinates
/// 输入： geodetic lat(deg N), lon(deg E),
//// height above ellipsoid (meters)
/// 输出： X,Y,Z in meters in cartesian (ECEF) coordinates
/// </summary>
public void GeodeticToCartesian(double lat, double lon, double height,
out double X, out double Y, out double Z) //大地坐标转化为笛卡尔坐标
{
double N = ell.N(lat); //计算卯酉圈曲率半径
double slat = Math.Sin(lat);
double clat = Math.Cos(lat);
X = (N + height) * clat * Math.Cos(lon);//具体的转化为XYZ的公式
Y = (N + height) * clat * Math.Sin(lon);
Z = (N * (1 - ell.eccSq) + height) * slat;
}
/// <summary>
/// convert geodetic to cartesian (ECEF) coordinates
/// 输入： geodetic lat(deg N), lon(deg E),
//// height above ellipsoid (meters)
/// 输出： X,Y,Z in meters in cartesian (ECEF) coordinates
/// </summary>
public void GeodeticToCartesian(double lat, double lon, double height,
out double X, out double Y, out double Z)//GeodeticToCartesian大地to笛卡尔
//BLH to XYZ
{
double N = ell.N(lat);
double slat = Math.Sin(lat);//lat是纬度 latitude
double clat = Math.Cos(lat);
X = (N + height) * clat * Math.Cos(lon); //lon是经度 longitude
Y = (N + height) * clat * Math.Sin(lon);
Z = (N * (1 - ell.eccSq) + height) * slat; //eccentricity偏心率
}
/////<summary>
///// BL --> xy
///// 转换B,L 到x,y(高斯平面坐标系)
///// </summary>
///// <param name="B"> 纬度（以弧度单位）</param>
///// <param name="L"> 经度（以弧度为单位），</param>
///// <param name="x">x方向坐标（以m为单位）</param>
///// <param name="y">y方向坐标（以m为单位）</param>
//public void GeodeticToGrid(double B, double L, out double x, out double y)
//{
// double N = ell.N(B); //A / Math.Sqrt(1.0 - eccSq * slat * slat);
// double X = MeridianArclength(B);
// L = (L - L0);
// double slat = Math.Sin(B);
// double m = L * Math.Cos(B);
// double m2 = m * m;
// double m3 = m2 * m;
// double m4 = m3 * m;
// double m5 = m4 * m;
// double m6 = m5 * m;
// double t = Math.Tan(B);
// double t2 = t * t;
// double t4 = t2 * t2;
// double eta = Math.Sqrt(ell.eccSq / (1 - ell.eccSq)) * Math.Cos(B);
// double eta2 = eta * eta;
// double eta4 = eta2 * eta2;
// x = X + N * t * (0.5 * m2 + 1 / 24 * (5 - t2 + 9 * eta2 + 4 * eta4) * m4
// + 1 / 720 * (61 - 58 * t2 + t4) * m6);
// y = N * (m + 1 / 6 * (1 - t2 + eta2) * m3 +
// 1 / 120 * (5 - 18 * t2 + t4 + 14 * eta2 - 58 * eta2 * t2) * m5);
// y = y + Y0;
//}
///// <summary>
///// xy -->BL
///// 高斯平面坐标转换为大地坐标
///// </summary>
///// <param name="x">x坐标（以m为单位）</param>
///// <param name="y">y坐标（以m为单位）</param>
///// <param name="lat">纬度（以°为单位）</param>
///// <param name="lon">经度（以°为单位）</param>
//public void GridToGeodetic(double x, double y, out double lat, out double lon)
//{
// //底点维度 EndPointLat(x,eccSq,B);
// double B_f = EndPointLat(x);
// double slat = Math.Sin(B_f);
// double clat = Math.Cos(B_f);
// double N = ell.a / Math.Sqrt(1.0 - ell.eccSq * slat * slat);
// double t = Math.Tan(B_f);
// double t2 = t * t;
// double t4 = t2 * t2;
// double etaSq = ell.eccSq / (1 - ell.eccSq) * clat * clat;
// double Y1 = (y - Y0) / N;
// double Y2 = Y1 * Y1;
// double Y3 = Y2 * Y1;
// double Y4 = Y3 * Y1;
// double Y5 = Y4 * Y1;
// double Y6 = Y5 * Y1;
// double V = 1 + etaSq;
// lat = B_f - 0.5 * t * V * Y2 + 1 / 24 * (5 + 3 * t2 + etaSq -
// 9 * etaSq * t2) * V * t * Y4 - 1 / 720 * (61 + 90 * t2 + 45 * t4) * V * t * Y6;
// lon = 1 / clat * (Y1 - 1 / 6 * (1 + 2 * t2 + etaSq) * Y3 +
// 1 / 120 * (5 + 28 * t2 + 24 * t4 + 6 * etaSq + 8 * etaSq * t2) * Y5);
// lon += L0;
//}
/// <summary>
/// 计算系数
/// </summary>
/// <param name="X">弧度长</param>
/// <param name="B">纬度</param>
/// <param name="aCoef">系数</param>
private void CoeffA(double X, double B, double[] aCoef)
{
double a0, a1, a2, a3, a4, a5, a6;
double N, t, eta;
N = ell.N(B);
t = ell.Tan(B);
eta = ell.Eta(B);
a0 = X;
a1 = N * Math.Cos(B);
a2 = N * t * Math.Pow(Math.Cos(B), 2) / 2.0;
a3 = N * (1 - t * t + eta * eta) * Math.Pow(Math.Cos(B), 3) / 6.0;
a4 = N * t * (5 - t * t + 9 * eta * eta + 4 * Math.Pow(eta, 4)) * Math.Pow(Math.Cos(B), 4) / 24.0;
a5 = N * (5 - 18 * t * t + Math.Pow(t, 4) + 14 * eta * eta - 58 * Math.Pow(eta, 2) * Math.Pow(t, 2)) * Math.Pow(Math.Cos(B), 5) / 120.0;
a6 = N * t * (61 - 58 * t * t + Math.Pow(t, 4) + 270 * eta * eta - 330 * Math.Pow(eta, 2) * Math.Pow(t, 2)) * Math.Pow(Math.Cos(B), 6) / 720.0;
aCoef[0] = a0;
aCoef[1] = a1;
aCoef[2] = a2;
aCoef[3] = a3;
aCoef[4] = a4;
aCoef[5] = a5;
aCoef[6] = a6;
}