//反算
public override void GetBLFromXY(decimal x, decimal y, ref decimal B, ref decimal L)
{
//this.GetBLFromXY(x, y, ref B, ref L, 0, EnumProjectionDatum.Xian80, this.Strip, this.L0, this.IsBigNumber);
//去掉大数和东移500公里
decimal y1 = y - 500000.0M;
if (this.IsBigNumber == true)
{
y1 = y1 - (this.L0 / (int)this.Strip) * 1000000M;
}
//计算临时参数
decimal E = K0 * x;
decimal CosE = Maths.Cos(E);
decimal SinE = Maths.Sin(E);
decimal SinE3 = SinE * SinE * SinE;
decimal SinE5 = SinE3 * SinE * SinE;
decimal SinE7 = SinE5 * SinE * SinE;
//求底点纬度
decimal Bf = E + CosE * (K1 * SinE - K2 * SinE3 + K3 * SinE5 - K4 * SinE7);
//计算临时参数
decimal CosBf = Maths.Cos(Bf);
decimal CosBf2 = CosBf * CosBf;
decimal t = Maths.Tan(Bf);
decimal η2 = e12 * CosBf2;
decimal C = a * a / b;
decimal V = Maths.Sqrt(1 + η2);
decimal N = C / V;
decimal V2 = V * V;
decimal t2 = t * t;
decimal t4 = t2 * t2;
decimal y1_N = y1 / N;
decimal y1_N2 = y1_N * y1_N;
decimal y1_N3 = y1_N2 * y1_N;
decimal y1_N4 = y1_N3 * y1_N;
decimal y1_N5 = y1_N4 * y1_N;
decimal y1_N6 = y1_N5 * y1_N;
decimal V2t = V * V * t;
//计算经纬度值B,L
B = Bf - (V2t * y1_N2) / 2 + ((5 + 3 * t2 + η2 - 9 * η2 * t2) * V2t * y1_N4 * 1.0M) / 24 - ((61 + 90 * t2 + 45 * t4) * V2t * y1_N6 * 1.0M) / 720;
L = y1_N * 1.0M / CosBf - (1 + 2 * t2 + η2) * (1.0M / CosBf) * y1_N3 / 6 + (5 + 28 * t2 + 24 * t2 + 6 * η2 + 8 * η2 * t2) * (1.0M / CosBf) * y1_N5 * 1.0M / 120;
AngleUnit_D dUnit = new AngleUnit_D(this.L0);
L = L + dUnit.getArcDValue(); //弧度
//弧度->度
AngleUnit_ArcD acUnit = new AngleUnit_ArcD(B);
dUnit = new AngleUnit_D(acUnit);
B = (decimal)dUnit.getAngle();
acUnit = new AngleUnit_ArcD(L);
dUnit = new AngleUnit_D(acUnit);
L = (decimal)dUnit.getAngle();
}
/// <summary>
/// 计算IGeometry的椭球面的 理论面积
/// </summary>
/// <param name="geo">输入的分幅图的几何对象IGeometry(矩形状)</param>
/// <returns>(单位：平方米)</returns>
public override decimal Compute(IGeometry geo)
{
decimal P = 0.0M;
//(1)最大最小角计算出WGS84大地经纬度坐标(四个点) 经差/纬差
decimal xmin = Maths.Todecimal(geo.Envelope.XMin);
decimal ymin = Maths.Todecimal(geo.Envelope.YMin);
decimal xmax = Maths.Todecimal(geo.Envelope.XMax);
decimal ymax = Maths.Todecimal(geo.Envelope.YMax);
//(2)转为经纬度坐标
decimal Bmin = 0.0M;//ToWGS84(xmin,ymin)
decimal Lmin = 0.0M;
decimal BMax = 0.0M;//ToWGS84(xmax,ymax)
decimal Lmax = 0.0M;
//double dL = Lmax - Lmin; //经差△L
//double dB = BMax - Bmin; //纬差(B2-B1)
//比例尺 5千
IMapScale scale = new MapScale_5000();
decimal dL = scale.L2_L1; //(单位：弧度)
decimal dB = scale.B2_B1; //(单位：弧度)
//default=西安椭球体参数
decimal b = this.EllipseParameter.b;
decimal a = this.EllipseParameter.a;
decimal A = this.EllipseParameter.A;
decimal B = this.EllipseParameter.B;
decimal C = this.EllipseParameter.C;
decimal D = this.EllipseParameter.D;
decimal E = this.EllipseParameter.E;
decimal Bm = (Bmin + BMax) / 2;
decimal CosBm = Maths.Cos(Bm);
decimal Cos3Bm = Maths.Cos(3 * Bm);
decimal Cos5Bm = Maths.Cos(5 * Bm);
decimal Cos7Bm = Maths.Cos(7 * Bm);
decimal Cos9Bm = Maths.Cos(9 * Bm);
P = ((4 * PI * b * b * dL) / (360 * 60)) * (A * Maths.Sin(dB * 1 / 2) * CosBm
- B * Maths.Sin(dB * 3 / 2) * Cos3Bm
+ C * Maths.Sin(dB * 5 / 2) * Cos5Bm
- D * Maths.Sin(dB * 7 / 2) * Cos7Bm
+ E * Maths.Sin(dB * 9 / 2) * Cos9Bm);
return(P); //(单位：平方米)
}
/// <summary>
/// 求(B1,L1)-(B2,L2)的任意梯形椭球面积
/// </summary>
/// <param name="B1"></param>
/// <param name="L1"></param>
/// <param name="B2"></param>
/// <param name="L2"></param>
/// <returns></returns>
public decimal Compute(decimal B1, decimal L1, decimal B2, decimal L2)
{
decimal P = 0;
decimal Lany = 60.0M;
decimal dL = (L2 + L1) / 2 - Lany; //经差△L
decimal dB = B2 - B1; //纬差(B2-B1)
dL = dL * PI / 180; //(单位：弧度)
dB = dB * PI / 180; //(单位：弧度)
//default=西安椭球体参数
decimal b = this.EllipseParameter.b;
decimal a = this.EllipseParameter.a;
decimal A = this.EllipseParameter.A;
decimal B = this.EllipseParameter.B;
decimal C = this.EllipseParameter.C;
decimal D = this.EllipseParameter.D;
decimal E = this.EllipseParameter.E;
decimal Bm = (B1 + B2) / 2;
Bm = Bm * PI / 180; //(单位：弧度)
decimal CosBm = Maths.Cos(Bm);
decimal Cos3Bm = Maths.Cos(3 * Bm);
decimal Cos5Bm = Maths.Cos(5 * Bm);
decimal Cos7Bm = Maths.Cos(7 * Bm);
decimal Cos9Bm = Maths.Cos(9 * Bm);
//求任意梯形椭球面积
P = (2 * b * b * dL) * (A * Maths.Sin(dB * 1 / 2) * CosBm
- B * Maths.Sin(dB * 3 / 2) * Cos3Bm
+ C * Maths.Sin(dB * 5 / 2) * Cos5Bm
- D * Maths.Sin(dB * 7 / 2) * Cos7Bm
+ E * Maths.Sin(dB * 9 / 2) * Cos9Bm);
return(P);
}
/// <summary>
/// 大地坐标转换为高斯投影坐标 正解公式
/// WGC84->高斯投影
/// Description:
///' 大地坐标转换为高斯投影坐标
///' Parameters:
///' LX,BX - 输入，经纬度坐标
///' x,y - 输出，高斯投影坐标(大数)
///' nearright - 输入，L是相邻两带的分界线时的取法，0 - 左带（小），1 - 右带（大）
///' ProjectionType - 输入，1 - 80坐标系，0 - 54坐标系
///' StripType - 输入，1 - 6度分带，0 - 3度分带
/// 当只有一个已知控制点时，根据平移参数调整东伪偏移、北纬偏移值实现WGS84到北京54的转换
/// 东伪偏移=东伪偏移值=tpMainStrip * 1000000+500000.0
/// 北纬偏移值=0;
/// </summary>
/// <param name="BX">大地纬度B</param>
/// <param name="LX">大地经度L</param>
/// <param name="x">高斯投影X</param>
/// <param name="y">高斯投影Y</param>
/// <param name="nearright">输入，L是相邻两带的分界线时的取法，0 - 左带（小），1 - 右带（大）</param>
/// <param name="ProjectionType"> 输入，1 - 80坐标系，0 - 54坐标系</param>
/// <param name="StripType"> 输入，1 - 6度分带，0 - 3度分带</param>
/// <param name="IsBigNumber">输入, 是大数坐标吗？</param>
public void GetXYFromBL(decimal BX, decimal LX, ref decimal x, ref decimal y, long nearright, EnumProjectionDatum ProjectionType, EnumStrip StripType, bool IsBigNumber)
{
decimal t = 0;
decimal B = 0;
decimal L = 0;
decimal x0 = 0;
decimal y2 = 0;
decimal E12 = 0;
decimal c0 = 0;
decimal n1 = 0;
decimal m = 0;
decimal temp1 = 0, temp2 = 0;
decimal LX1 = 0;
decimal fc_pi = 3.14159265358979M; //PI值
B = (BX / 180) * fc_pi; //转为弧度值bx*(PI/180)
L = (LX / 180) * fc_pi; //转为弧度值lx*(PI/180)
//求带内中央子午线经度
LX1 = GetLocalLongitude(LX, nearright, StripType);
m = Maths.Cos(B) * fc_pi * LX1 / 180.0M;
t = Maths.Tan(B);
switch (ProjectionType)
{
case EnumProjectionDatum.Xian80: //80坐标
c0 = 6399596.65198801M;
E12 = 0.0067395018195M;
x0 = 111133.0047M * BX - (32009.8575M * Maths.Sin(B) + 133.9978M * (Maths.Pow(Maths.Sin(B), 3)) + 0.6975M * (Maths.Pow(Maths.Sin(B), 5)) + 0.0039M * (Maths.Pow(Maths.Sin(B), 7))) * Maths.Cos(B);
break;
case EnumProjectionDatum.Bejing54: //54坐标
c0 = 6399698.90178271M;
E12 = 0.00673852541468M;
x0 = 111134.8611M * BX - (32005.7798M * Maths.Sin(B) + 133.9614M * (Maths.Pow(Maths.Sin(B), 3)) + 0.6972M * (Maths.Pow(Maths.Sin(B), 5)) + 0.0039M * (Maths.Pow(Maths.Sin(B), 7))) * Maths.Cos(B);
break;
default: //其它暂为空
break;
}
y2 = E12 * (Maths.Pow(Maths.Cos(B), 2));
n1 = c0 / Maths.Sqrt(1.0M + y2);
temp1 = (Maths.Pow(m, 2)) / 2.0M + (5.0M - (Maths.Pow(t, 2)) + 9.0M * y2 + 4 * (Maths.Pow(y2, 2))) * (Maths.Pow(m, 4)) / 24.0M + (61.0M - 58.0M * (Maths.Pow(t, 2)) + (Maths.Pow(t, 4))) * (Maths.Pow(m, 6)) / 720.0M;
temp2 = m + (1.0M - (Maths.Pow(t, 2)) + y2) * (Maths.Pow(m, 3)) / 6.0M + (5.0M - 18.0M * (Maths.Pow(t, 2)) + (Maths.Pow(t, 4)) + 14.0M * y2 - 58.0M * y2 * (Maths.Pow(t, 2))) * (Maths.Pow(m, 5)) / 120.0M;
x = x0 + n1 * t * temp1;
y = n1 * temp2 + 500000.0M; //与中央经线的距离m //500000.0表示平移了500公里距离 目的是把负数坐标转为正数好处理
//主带数值（整数）
decimal tpMainStrip = 0; //主带数值
switch (StripType)
{
case EnumStrip.Strip3:
tpMainStrip = (int)Math.Truncate(LX / 3) + 1;
break;
case EnumStrip.Strip6:
tpMainStrip = (int)Math.Truncate(LX / 6) + 1;
break;
default: //则自动计算 ,默认为3度带
tpMainStrip = (int)Math.Truncate(LX / 3) + 1;
break;
}
//转为大数坐标y=带数*1000000+与中央经线的距离m
//东伪偏移值=tpMainStrip * 1000000+500000.0
if (IsBigNumber == true) //转为高斯投影是大数投影吗？即Zone 35带数 （小数投影为CM_105E)
{
y = y + tpMainStrip * 1000000;
}
}
/// <summary>
/// 计算IGeometry的椭球面的 理论面积
/// </summary>
/// <param name="geo">输入的分幅图的几何对象IGeometry(矩形状)</param>
/// <returns>(单位：平方米)</returns>
public override decimal Compute(IGeometry geo)
{
decimal P = 0.0M;
decimal Lany = 60.0M;
decimal ShapeArea = 0;
//(1)最大最小角计算出WGS84大地经纬度坐标(四个点) 经差/纬差
decimal xmin = Maths.Todecimal(geo.Envelope.XMin);
decimal ymin = Maths.Todecimal(geo.Envelope.YMin);
decimal xmax = Maths.Todecimal(geo.Envelope.XMax);
decimal ymax = Maths.Todecimal(geo.Envelope.YMax);
ShapeArea = Maths.Todecimal((geo as IArea).Area);
//double blxs = (geo as IArea).Area / (geo.Envelope as IArea).Area;
//(2)转为经纬度坐标 //ToWGS84(xmax,ymax)
decimal Bmin = 0, Lmin = 0, Bmax = 0, Lmax = 0;
this.gassConv.GetBLFromXY(ymin, xmin, ref Bmin, ref Lmin, 0, this.Datum, this.Strip, this.L0, this.IsBigNumber); //ToWGS84(xmin,ymin)
this.gassConv.GetBLFromXY(ymax, xmax, ref Bmax, ref Lmax, 0, this.Datum, this.Strip, this.L0, this.IsBigNumber); //ToWGS84(xmin,ymin)
decimal dL = (Lmax + Lmin) / 2 - Lany; //经差△L
decimal dB = Bmax - Bmin; //纬差(B2-B1)
dL = dL * PI / 180; //(单位：弧度)
dB = dB * PI / 180; //(单位：弧度)
//default=西安椭球体参数
decimal b = this.EllipseParameter.b;
decimal a = this.EllipseParameter.a;
decimal A = this.EllipseParameter.A;
decimal B = this.EllipseParameter.B;
decimal C = this.EllipseParameter.C;
decimal D = this.EllipseParameter.D;
decimal E = this.EllipseParameter.E;
decimal Bm = (Bmin + Bmax) / 2;
Bm = Bm * PI / 180; //(单位：弧度)
decimal CosBm = Maths.Cos(Bm);
decimal Cos3Bm = Maths.Cos(3 * Bm);
decimal Cos5Bm = Maths.Cos(5 * Bm);
decimal Cos7Bm = Maths.Cos(7 * Bm);
decimal Cos9Bm = Maths.Cos(9 * Bm);
//求geo几何体的包络矩形的椭球面积
P = (2 * b * b * dL) * (A * Maths.Sin(dB * 1 / 2) * CosBm
- B * Maths.Sin(dB * 3 / 2) * Cos3Bm
+ C * Maths.Sin(dB * 5 / 2) * Cos5Bm
- D * Maths.Sin(dB * 7 / 2) * Cos7Bm
+ E * Maths.Sin(dB * 9 / 2) * Cos9Bm);
//正算经纬度矩形的另外两个点的投影坐标值
decimal x2 = 0, y2 = 0, x4 = 0, y4 = 0;
this.gassConv.GetXYFromBL(Bmin, Lmax, ref y2, ref x2, 0, this.Datum, EnumStrip.Strip3, this.IsBigNumber);
this.gassConv.GetXYFromBL(Bmax, Lmin, ref y4, ref x4, 0, this.Datum, EnumStrip.Strip3, this.IsBigNumber);
//求经纬度矩形的投影梯形面积(上底+下底)*高/2
decimal BLTrapeziaArea = ((x2 - xmin) + (xmax - x4)) * (ymax - ymin) / 2;
decimal LLmj = P * ShapeArea / BLTrapeziaArea;
return(LLmj); //(单位：平方米)
}