/// <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;
}
}
public decimal GetRingEllipse(IGeometry geo)
{
IPointCollection pointColl = geo as IPointCollection;
IPoint point = null;
decimal x = 0;
decimal y = 0;
decimal[] B = new decimal[pointColl.PointCount];
decimal[] L = new decimal[pointColl.PointCount];
int intPart = 0;
if (this.Datum == EnumProjectionDatum.Xian80)
{ //西安80系
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
intPart = (int)x;
if (intPart.ToString().Length == 6)
{ //x坐标实质是小数坐标
this.IsBigNumber = false;
}
if (intPart.ToString().Length == 8)
{ //x坐标实质是小数坐标
this.IsBigNumber = true;
}
//高斯反算
if (this.gassConv is GSCoordConVertionClass_Xian80_Call2)
{
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).IsBigNumber = this.IsBigNumber;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).Strip = this.Strip;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).L0 = this.L0;
(this.gassConv as GSCoordConVertionClass_Xian80_Call2).GetBLFromXY(y, x, ref B[i], ref L[i]);
}
else
{
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
}
else if (this.Datum == EnumProjectionDatum.CGCS2000)
{ //2000坐标系
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
intPart = (int)x;
if (intPart.ToString().Length == 6)
{ //x坐标实质是小数坐标
this.IsBigNumber = false;
}
if (intPart.ToString().Length == 8)
{ //x坐标实质是小数坐标
this.IsBigNumber = true;
}
//高斯反算
if (this.gassConv is GSCoordConvertionClass_CGCS_2000)
{
(this.gassConv as GSCoordConvertionClass_CGCS_2000).IsBigNumber = this.IsBigNumber;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).Strip = this.Strip;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).L0 = this.L0;
(this.gassConv as GSCoordConvertionClass_CGCS_2000).GetBLFromXY(y, x, ref B[i], ref L[i]);
}
else
{
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
}
else
{ //北京54
for (int i = 0; i < pointColl.PointCount; i++)
{
point = pointColl.get_Point(i);
x = Maths.Todecimal(point.X); y = Maths.Todecimal(point.Y);
//高斯反算
this.gassConv.GetBLFromXY(y, x, ref B[i], ref L[i], 1, this.Datum, this.Strip, this.L0, this.IsBigNumber);
}
}
decimal sum = 0;
for (int i = 0; i < B.Length; i++)
{
if (i < B.Length - 1)
{
//double n = GetSign(L[i], L[i + 1]) * (Math.Abs(B[i] + B[i + 1]) * Math.Abs(L[i + 1] - L[i])) / 2;
decimal n = this.Compute(B[i + 1], L[i + 1], B[i], L[i]);
//System.Diagnostics.Debug.WriteLine(n.ToString());
sum += n;
}
else
{
//double r = GetSign(L[B.Length - 1], L[0]) * (Math.Abs(B[0] + B[B.Length - 1]) * Math.Abs(L[0] - L[B.Length - 1])) / 2;
decimal r = this.Compute(B[0], L[0], B[B.Length - 1], L[L.Length - 1]);
//System.Diagnostics.Debug.WriteLine(r.ToString());
sum += r;
}
}
sum = Math.Abs(sum);
return(sum);
}
/// <summary>
/// 高斯投影坐标转换为大地坐标 反解公式
/// Parameters:
/// x,y - 输入，高斯投影坐标(大数)
/// LX,BX - 输出，经纬度坐标
/// 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
/// L0 - 输入, 3度或6度分带的中央子午线 单位为度
/// </summary>
/// <param name="x"> 输入，高斯投影X坐标</param>
/// <param name="y"> 输入，高斯投影Y坐标(大数)</param>
/// <param name="BX">输入，纬度坐标</param>
/// <param name="LX">输入，经度坐标</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="L0">输入, 3度或6度分带的中央子午线 单位为度</param>
/// <param name="IsBigNumber">输入, 是大数坐标吗？</param>
/// <returns></returns>
public bool GetBLFromXY(decimal x, decimal y, ref decimal BX, ref decimal LX, int nearright, EnumProjectionDatum ProjectionType, EnumStrip StripType, decimal L0, bool IsBigNumber)
{
decimal a0 = 0;
decimal b0 = 0;
decimal c0 = 0;
decimal E12 = 0;
decimal bf0 = 0;
decimal bf = 0;
decimal tf = 0;
decimal yf2 = 0;
decimal n = 0;
decimal b1 = 0;
decimal l1 = 0;
decimal temp1 = 0;
long iStripNum = 0;
decimal fc_pi = 3.14159265358979M;
//要素的Y坐标中是否含有大地坐标的大数？
switch (StripType)
{
case EnumStrip.Strip6:
iStripNum = (long)Math.Round(L0 / 6);
break;
case EnumStrip.Strip3:
iStripNum = (long)Math.Round(L0 / 3);
break;
}
//认为高斯投影Y坐标为大数(y=带数*1000000 + 与中央经线的距离m
//要素的Y坐标包含有大地坐标吗？y=y+带数*1000000 + 与中央经线的距离m(500公里)
if (IsBigNumber == true)
{
y = y - iStripNum * 1000000;
}
x = x / 1000000;
y = y - 500000;
switch (ProjectionType)
{
case EnumProjectionDatum.Bejing54: //北京54
a0 = 6378245M; //长半轴 a（米）
b0 = 6356863.01877305M; //短半轴b（米）
c0 = 6399698.90178271M;
E12 = 0.0067385254147M;
bf0 = 27.11115372595M + 9.02468257083M * (x - 3) - 0.00579740442M * (Maths.Pow((x - 3), 2)) - 0.00043532572M * (Maths.Pow((x - 3), 3)) + 0.00004857285M * (Maths.Pow((x - 3), 4)) + 0.00000215727M * (Maths.Pow((x - 3), 5)) - 0.00000019399M * (Maths.Pow((x - 3), 6));
break;
case EnumProjectionDatum.Xian80: //西安80
a0 = 6378140M; //长半轴 a（米）
b0 = 6356755.28815753M; //短半轴b（米）
c0 = 6399596.65198801M;
E12 = 0.0067395018195M;
bf0 = 27.11162289465M + 9.02483657729M * (x - 3) - 0.00579850656M * (Maths.Pow((x - 3), 2)) - 0.00043540029M * (Maths.Pow((x - 3), 3)) + 0.00004858357M * (Maths.Pow((x - 3), 4)) + 0.00000215769M * (Maths.Pow((x - 3), 5)) - 0.00000019404M * (Maths.Pow((x - 3), 6));
break;
default: //暂为空
break;
}
bf = bf0 * fc_pi / 180;
tf = Maths.Tan(bf);
yf2 = E12 * (Maths.Pow(Maths.Cos(bf), 2));
n = y * Maths.Sqrt(1 + yf2) / c0;
temp1 = 90.0M * (Maths.Pow(n, 2)) - 7.5M * (5.0M + 3.0M * (Maths.Pow(tf, 2)) + yf2 - 9.0M * yf2 * (Maths.Pow(tf, 2))) * (Maths.Pow(n, 4)) + 0.25M * (61.0M + 90.0M * (Maths.Pow(tf, 2)) + 45.0M * (Maths.Pow(tf, 4))) * (Maths.Pow(n, 6));
b1 = bf0 - (1.0M + yf2) * tf * temp1 / fc_pi;
l1 = (180.0M * n - 30.0M * (1.0M + 2.0M * (Maths.Pow(tf, 2)) + yf2) * (Maths.Pow(n, 3)) + 1.5M * (5.0M + 28.0M * (Maths.Pow(tf, 2)) + 24.0M * (Maths.Pow(tf, 4))) * (Maths.Pow(n, 5))) / fc_pi / Maths.Cos(bf);
l1 = l1 + L0;
if (l1 < 0.0M)
{
l1 = l1 + 360.0M;
}
if (l1 >= 360.0M)
{
l1 = l1 - 360.0M;
}
BX = b1;
LX = l1;
return(true);
}
/// <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)
}