/// <summary>
/// 平面坐标转经纬坐标
/// 1.若平面坐标point的Y为6位，需指定center中央子午线经度
/// </summary>
/// <param name="point">平面坐标</param>
/// <param name="center">中央子午线经度，若为null，Y为8位带带号数字，否则Y应为6位数字</param>
/// <param name="bandtype"></param>
/// <param name="coordinate"></param>
/// <returns>X纬，Y经</returns>
public static Point Plane2Geo(Point point, double?center = null, EBandType bandtype = EBandType.度带, ECoordinate coordinate = ECoordinate.北京54)
{
double t_f;
double Eta_f;
double B_f;
double N_f;
double M_f;
double B0;
double K0, K2, K4, K6;
double dh;
double y = point.Y;
double x = point.X;
if (center == null)
{
dh = (int)(y / 1000000); //带号
y = (y % 1000000) - 500000;
}
else
{
dh = 0;
y = y - 500000;
}
double a, b, e1, e2; //椭球参数
getpara(coordinate, out a, out b);
e1 = Math.Sqrt(a * a - b * b) / a;
e2 = Math.Sqrt(a * a - b * b) / b;
double A0;
A0 = 1.0 + 3.0 / 4 * e1 * e1 + 45.0 / 64 * Math.Pow(e1, 4) + 350.0 / 512 * Math.Pow(e1, 6) + 11025.0 / 16384 * Math.Pow(e1, 8);
B0 = x / (a * (1 - e1 * e1) * A0);
K0 = 1.0 / 2 * (3.0 / 4 * e1 * e1 + 45.0 / 64 * Math.Pow(e1, 4) + 350.0 / 512 * Math.Pow(e1, 6) + 11025.0 / 16384 * Math.Pow(e1, 8));
K2 = -1.0 / 3 * (63.0 / 64 * Math.Pow(e1, 4) + 1108.0 / 512 * Math.Pow(e1, 6) + 58239.0 / 16384 * Math.Pow(e1, 8));
K4 = 1.0 / 3 * (604.0 / 512 * Math.Pow(e1, 6) + 68484.0 / 16384 * Math.Pow(e1, 8));
K6 = -1.0 / 3 * (26328.0 / 16384 * Math.Pow(e1, 8));
B_f = B0 + Math.Sin(2 * B0) * (K0 + Math.Sin(B0) * Math.Sin(B0) * (K4 + K6 * Math.Sin(B0) * Math.Sin(B0)));
t_f = Math.Tan(B_f);
Eta_f = e2 * Math.Cos(B_f);
N_f = a / Math.Sqrt(1 - e1 * e1 * Math.Sin(B_f) * Math.Sin(B_f));
M_f = N_f / (1 + e2 * e2 * Math.Cos(B_f) * Math.Cos(B_f));
double B;
B = B_f - t_f / (2 * M_f * N_f) * y * y +
t_f / (24 * M_f * Math.Pow(N_f, 3)) * (5 + 3 * t_f * t_f + Eta_f * Eta_f - 9 * Eta_f * Eta_f * t_f * t_f) * Math.Pow(y, 4) -
t_f / (720 * M_f * Math.Pow(N_f, 5)) * (61 + 90 * t_f * t_f + 45 * Math.Pow(t_f, 4)) * Math.Pow(y, 6);
double l;
l = 1.0 / (N_f * Math.Cos(B_f)) * y -
1.0 / (6 * Math.Pow(N_f, 3) * Math.Cos(B_f)) * (1 + 2 * t_f * t_f + Eta_f * Eta_f) * Math.Pow(y, 3) +
1.0 / (120 * Math.Pow(N_f, 5) * Math.Cos(B_f)) * (5 + 28 * t_f * t_f + 24 * Math.Pow(t_f, 4) + 6 * Eta_f * Eta_f + 8 * Eta_f * Eta_f * t_f * t_f) * Math.Pow(y, 5);
//将B转化为度分秒的形式
double dDegB;
dDegB = B * 180 / Math.PI;
double dDegL;
dDegL = l * 180 / Math.PI;
if (center == null)
{
if (bandtype == EBandType.度带)
{
center = dh * 3;
}
else if (bandtype == EBandType.六度带)
{
center = dh * 6 - 3;
}
}
return(new Point(dDegB, dDegL + (double)center));
}
/// <summary>
/// 经纬转平面坐标
/// 1.若参数center为null，则按三或六度带自动确定中央子午线经度，返回结果的Y为8位，前两位为带号
/// 2.若参数center指定中央子午线经度，返回结果Y为6位
/// </summary>
/// <param name="geopoint">经纬度坐标，x纬y经</param>
/// <param name="center">中央子午度经度</param>
/// <param name="bandtype"></param>
/// <param name="coordinate"></param>
/// <returns>若center=null, Y为8位，前两位为带号, 否则为6位</returns>
public static Point geo2Plane(Point geopoint, double?center = null, EBandType bandtype = EBandType.度带, ECoordinate coordinate = ECoordinate.北京54)
{
double N;
double t;
double Eta;
double X;
double A0, A2, A4, A6, A8;
double RadB;
double Rou;
Rou = 180 * 3600 / Math.PI;
double longitude = geopoint.Y; //.Longitude;
double latitude = geopoint.X; //.Latitude;
double a, b, e1, e2; //椭球参数
getpara(coordinate, out a, out b);
e1 = Math.Sqrt(a * a - b * b) / a;
e2 = Math.Sqrt(a * a - b * b) / b;
double l;
double L0;
int n;
if (center != null) //指定中央经线
{
L0 = (int)center;
n = 0;
}
else
{
if (bandtype == EBandType.度带)
{
n = (int)((longitude + 1.5) / 3);
L0 = 3 * n;
}
else
{
n = (int)(longitude / 6) + 1;
L0 = 6 * n - 3;
}
}
//L0 = 111;
double L;
L = longitude;
l = (L - L0) * 3600;
RadB = (latitude) * Math.PI / 180;
N = a / Math.Sqrt(1 - e1 * e1 * Math.Sin(RadB) * Math.Sin(RadB));
t = Math.Tan(RadB);
Eta = e2 * Math.Cos(RadB);
A0 = 1.0 + 3.0 / 4 * e1 * e1 + 45.0 / 64 * Math.Pow(e1, 4) + 350.0 / 512 * Math.Pow(e1, 6) + 11025.0 / 16384 * Math.Pow(e1, 8);
A2 = -1.0 / 2 * (3.0 / 4 * e1 * e1 + 60.0 / 64 * Math.Pow(e1, 4) + 525.0 / 512 * Math.Pow(e1, 6) + 17640.0 / 16384 * Math.Pow(e1, 8));
A4 = 1.0 / 4 * (15.0 / 64 * Math.Pow(e1, 4) + 210.0 / 512 * Math.Pow(e1, 6) + 8820.0 / 16384 * Math.Pow(e1, 8));
A6 = -1.0 / 6 * (35.0 / 512 * Math.Pow(e1, 6) + 2520.0 / 16384 * Math.Pow(e1, 8));
A8 = 1.0 / 8 * (315.0 / 16384 * Math.Pow(e1, 8));
X = a * (1 - e1 * e1) * (A0 * RadB + A2 * Math.Sin(2 * RadB) + A4 * Math.Sin(4 * RadB) + A6 * Math.Sin(6 * RadB) + A8 * Math.Sin(8 * RadB));
//计算平面横轴
double plane_X = X + N / (2 * Rou * Rou) * Math.Sin(RadB) * Math.Cos(RadB) * l * l +
N / (24 * Math.Pow(Rou, 4)) * Math.Sin(RadB) * Math.Pow(Math.Cos(RadB), 3) * (5 - t * t + 9 * Eta * Eta + 4 * Math.Pow(Eta, 4)) * Math.Pow(l, 4) +
N / (720 * Math.Pow(Rou, 6)) * Math.Sin(RadB) * Math.Pow(Math.Cos(RadB), 5) * (61 - 58 * t * t + Math.Pow(t, 4)) * Math.Pow(l, 6);
//计算平面纵轴
double plane_Y = N / Rou * Math.Cos(RadB) * l +
N / (6 * Math.Pow(Rou, 3)) * Math.Pow(Math.Cos(RadB), 3) * (1 - t * t + Eta * Eta) * Math.Pow(l, 3) +
N / (120 * Math.Pow(Rou, 5)) * Math.Pow(Math.Cos(RadB), 5) * (5 - 18 * t * t + Math.Pow(t, 4) + 14 * Eta * Eta - 58 * Eta * Eta * t * t) * Math.Pow(l, 5);
double py;
if (center == null)
{
py = double.Parse(n.ToString() + (plane_Y + 500000).ToString());
}
else
{
py = plane_Y + 500000;
}
return(new Point(plane_X, py));
}
