private Cartographic3 fromCartesian(Cartesian3 cartesian3, Ellipsoid ellipsoid)
{
Cartesian3Service cartesian3Service = new Cartesian3Service();
var cartesianToCartographicN = new Cartesian3();
var cartesianToCartographicP = new Cartesian3();
var cartesianToCartographicH = new Cartesian3();
Cartesian3 oneOverRadii = ellipsoid.OneOverRadii;
Cartesian3 oneOverRadiiSquared = ellipsoid.OneOverRadiiSquared;
double centerToleranceSquared = ellipsoid.CenterToleranceSquared;
Cartesian3 p = scaleToGeodeticSurface(cartesian3, ellipsoid, cartesian3Service);
if (p == null)
{
return(null);
}
cartesianToCartographicN = cartesian3Service.MultiplyComponents(p, oneOverRadiiSquared);
cartesianToCartographicN = cartesian3Service.Normalize(cartesianToCartographicN);
cartesianToCartographicH = cartesian3Service.Subtract(cartesian3, p);
var longitude = Math.Atan2(cartesianToCartographicN.Y, cartesianToCartographicN.X);
var latitude = Math.Asin(cartesianToCartographicN.Z);
var height = Math.Sign(cartesian3Service.Dot(cartesianToCartographicH, cartesian3)) * cartesian3Service.Magnitude(cartesianToCartographicH);
Cartographic3 result = new Cartographic3();
result.Longitude = longitude;
result.Latitude = latitude;
result.Height = height;
return(result);
}
/// <summary>
/// 源坐标转目标坐标
/// </summary>
/// <param name="sourceCoordinate"></param>
/// <returns></returns>
public ICoordinate3 SourceToTarget(ICoordinate3 sourceCoordinate)
{
if (sourceCoordinate == null)
{
return(null);
}
Cartesian3 cartesian3 = null;
Cartographic3 cartographic3 = null;
Projection projection = null;
// ------------------------
// 第一步：源坐标转换为地理坐标
// ------------------------
switch (sourceCoordinateType)
{
case CoordinateType.Cartographic:
// 如果源是地理坐标，则不需要处理
cartographic3 = new Cartographic3(sourceCoordinate.XAxis, sourceCoordinate.YAxis, sourceCoordinate.ZAxis);
break;
case CoordinateType.Cartesian:
// 如果源是笛卡尔坐标
// 处理方法：
// 1.高斯反算,转为地理坐标
cartesian3 = new Cartesian3(sourceCoordinate.XAxis, sourceCoordinate.YAxis, sourceCoordinate.ZAxis);
GaussKrugerTransformation gauss_source_1 = new GaussKrugerTransformation(sourceEllipsoid);
cartographic3 = gauss_source_1.GaussKrugerReverse(cartesian3, sourceCenterMeridian);
break;
case CoordinateType.Projection:
// 如果源是投影坐标
// 处理方法：
// 1.投影坐标转笛卡尔坐标
// 2.高斯反算,转为地理坐标
GaussKrugerTransformation gauss_source_2 = new GaussKrugerTransformation(sourceEllipsoid);
projection = new Projection(sourceCoordinate.XAxis, sourceCoordinate.YAxis, sourceCoordinate.ZAxis);
cartesian3 = gauss_source_2.ProjectionToCartesian(projection);
cartographic3 = gauss_source_2.GaussKrugerReverse(cartesian3, sourceCenterMeridian);
break;
default:
break;
}
// ------------------------
// 第二步：地理坐标转换为笛卡尔空间坐标
// ------------------------
Cartesian3Service cartesian3Service = new Cartesian3Service();
cartesian3 = cartesian3Service.Cartographic3ToCartesian3(cartographic3, sourceEllipsoid);
// ------------------------
// 第三步：通过七参数模型，对笛卡尔空间坐标进行转换，转换后同样是笛卡尔空间坐标
// ------------------------
BursaWolfTransformation bursaWolfTransformation = new BursaWolfTransformation(sevenParams);
cartesian3 = bursaWolfTransformation.Transform(cartesian3);
// ------------------------
// 第四步：笛卡尔空间坐标转换为地理坐标
// ------------------------
Cartographic3Service cartographic3Service = new Cartographic3Service();
cartographic3 = cartographic3Service.Cartesian3ToCartographic3(cartesian3, targetEllipsoid);
// ------------------------
// 第五步：地理坐标转换为目标坐标
// ------------------------
ICoordinate3 result = null;
switch (targetCoordinateType)
{
case CoordinateType.Cartographic:
// 如果目标是地理坐标，则不需要处理
result = cartographic3.Clone();
break;
case CoordinateType.Cartesian:
// 如果目标是笛卡尔坐标
// 处理方法：
// 1.高斯正算,转为笛卡尔坐标系
GaussKrugerTransformation gauss_target_1 = new GaussKrugerTransformation(targetEllipsoid);
cartesian3 = gauss_target_1.GaussKrugerForward(cartographic3, targetCenterMeridian);
result = cartesian3.Clone();
break;
case CoordinateType.Projection:
// 如果目标是投影坐标
// 处理方法：
// 1.高斯正算,转为笛卡尔坐标系
// 2.笛卡尔坐标转投影坐标
GaussKrugerTransformation gauss_target_2 = new GaussKrugerTransformation(targetEllipsoid);
cartesian3 = gauss_target_2.GaussKrugerForward(cartographic3, targetCenterMeridian);
projection = gauss_target_2.CartesianToProjection(cartesian3);
result = projection.Clone();
break;
default:
break;
}
return(result);
}
private Cartesian3 scaleToGeodeticSurface(Cartesian3 cartesian3, Ellipsoid ellipsoid, Cartesian3Service cartesian3Service)
{
Cartesian3 oneOverRadii = ellipsoid.OneOverRadii;
Cartesian3 oneOverRadiiSquared = ellipsoid.OneOverRadiiSquared;
double centerToleranceSquared = ellipsoid.CenterToleranceSquared;
var positionX = cartesian3.X;
var positionY = cartesian3.Y;
var positionZ = cartesian3.Z;
var oneOverRadiiX = oneOverRadii.X;
var oneOverRadiiY = oneOverRadii.Y;
var oneOverRadiiZ = oneOverRadii.Z;
var x2 = positionX * positionX * oneOverRadiiX * oneOverRadiiX;
var y2 = positionY * positionY * oneOverRadiiY * oneOverRadiiY;
var z2 = positionZ * positionZ * oneOverRadiiZ * oneOverRadiiZ;
// Compute the squared ellipsoid norm.
var squaredNorm = x2 + y2 + z2;
var ratio = Math.Sqrt(1.0 / squaredNorm);
// As an initial approximation, assume that the radial intersection is the projection point.
var intersection = cartesian3Service.MultiplyByScalar(cartesian3, ratio);
// If the position is near the center, the iteration will not converge.
if (squaredNorm < centerToleranceSquared)
{
return(double.IsInfinity(ratio) ? null : intersection);
}
var oneOverRadiiSquaredX = oneOverRadiiSquared.X;
var oneOverRadiiSquaredY = oneOverRadiiSquared.Y;
var oneOverRadiiSquaredZ = oneOverRadiiSquared.Z;
// Use the gradient at the intersection point in place of the true unit normal.
// The difference in magnitude will be absorbed in the multiplier.
var gradient = new Cartesian3();
gradient.X = intersection.X * oneOverRadiiSquaredX * 2.0;
gradient.Y = intersection.Y * oneOverRadiiSquaredY * 2.0;
gradient.Z = intersection.Z * oneOverRadiiSquaredZ * 2.0;
// Compute the initial guess at the normal vector multiplier, lambda.
var lambda = (1.0 - ratio) * cartesian3Service.Magnitude(cartesian3) / (0.5 * cartesian3Service.Magnitude(gradient));
var correction = 0.0;
double func;
double denominator;
double xMultiplier;
double yMultiplier;
double zMultiplier;
double xMultiplier2;
double yMultiplier2;
double zMultiplier2;
double xMultiplier3;
double yMultiplier3;
double zMultiplier3;
do
{
lambda -= correction;
xMultiplier = 1.0 / (1.0 + lambda * oneOverRadiiSquaredX);
yMultiplier = 1.0 / (1.0 + lambda * oneOverRadiiSquaredY);
zMultiplier = 1.0 / (1.0 + lambda * oneOverRadiiSquaredZ);
xMultiplier2 = xMultiplier * xMultiplier;
yMultiplier2 = yMultiplier * yMultiplier;
zMultiplier2 = zMultiplier * zMultiplier;
xMultiplier3 = xMultiplier2 * xMultiplier;
yMultiplier3 = yMultiplier2 * yMultiplier;
zMultiplier3 = zMultiplier2 * zMultiplier;
func = x2 * xMultiplier2 + y2 * yMultiplier2 + z2 * zMultiplier2 - 1.0;
// "denominator" here refers to the use of this expression in the velocity and acceleration
// computations in the sections to follow.
denominator = x2 * xMultiplier3 * oneOverRadiiSquaredX + y2 * yMultiplier3 * oneOverRadiiSquaredY + z2 * zMultiplier3 * oneOverRadiiSquaredZ;
var derivative = -2.0 * denominator;
correction = func / derivative;
} while (Math.Abs(func) > 0.000000000001);
Cartesian3 result = new Cartesian3();
result.X = positionX * xMultiplier;
result.Y = positionY * yMultiplier;
result.Z = positionZ * zMultiplier;
return(result);
}
/// <summary>
/// 目标坐标转源坐标(批量)
/// </summary>
/// <param name="targetCoordinates"></param>
/// <returns></returns>
public List <ICoordinate3> TargetToSourceBatch(IEnumerable <ICoordinate3> targetCoordinates)
{
if (targetCoordinates == null || targetCoordinates.Count() == 0)
{
return(null);
}
List <ICoordinate3> result = new List <ICoordinate3>();
// 局部变量
Cartesian3 cartesian3 = null;
Cartographic3 cartographic3 = null;
Projection projection = null;
// 高斯转换
GaussKrugerTransformation gauss_source = new GaussKrugerTransformation(sourceEllipsoid);
GaussKrugerTransformation gauss_target = new GaussKrugerTransformation(targetEllipsoid);
// 布尔萨转换（参数反转）
BursaWolfTransformation bursaWolfTransformation = new BursaWolfTransformation(sevenParams.Reverse());
// 笛卡尔组表转换
Cartesian3Service cartesian3Service = new Cartesian3Service();
// 地理坐标转换
Cartographic3Service cartographic3Service = new Cartographic3Service();
// 遍历集合中的坐标
foreach (ICoordinate3 targetCoordinate in targetCoordinates)
{
// ------------------------
// 第一步：目标坐标转换为地理坐标
// ------------------------
switch (targetCoordinateType)
{
case CoordinateType.Cartographic:
// 如果目标是地理坐标，则不需要处理
cartographic3 = new Cartographic3(targetCoordinate.XAxis, targetCoordinate.YAxis, targetCoordinate.ZAxis);
break;
case CoordinateType.Cartesian:
// 如果目标是笛卡尔坐标
// 处理方法：
// 1.高斯反算,转为地理坐标
cartesian3 = new Cartesian3(targetCoordinate.XAxis, targetCoordinate.YAxis, targetCoordinate.ZAxis);
cartographic3 = gauss_target.GaussKrugerReverse(cartesian3, targetCenterMeridian);
break;
case CoordinateType.Projection:
// 如果目标是投影坐标
// 处理方法：
// 1.投影坐标转笛卡尔坐标
// 2.高斯反算,转为地理坐标
projection = new Projection(targetCoordinate.XAxis, targetCoordinate.YAxis, targetCoordinate.ZAxis);
cartesian3 = gauss_target.ProjectionToCartesian(projection);
cartographic3 = gauss_target.GaussKrugerReverse(cartesian3, targetCenterMeridian);
break;
default:
break;
}
// ------------------------
// 第二步：地理坐标转换为笛卡尔空间坐标
// ------------------------
cartesian3 = cartesian3Service.Cartographic3ToCartesian3(cartographic3, targetEllipsoid);
// ------------------------
// 第三步：通过七参数模型，对笛卡尔空间坐标进行转换，转换后同样是笛卡尔空间坐标（这里需要反转参数）
// ------------------------
cartesian3 = bursaWolfTransformation.Transform(cartesian3);
// ------------------------
// 第四步：笛卡尔空间坐标转换为地理坐标
// ------------------------
cartographic3 = cartographic3Service.Cartesian3ToCartographic3(cartesian3, sourceEllipsoid);
// ------------------------
// 第五步：地理坐标转换为源坐标
// ------------------------
ICoordinate3 subResult = null;
switch (sourceCoordinateType)
{
case CoordinateType.Cartographic:
// 如果源是地理坐标，则不需要处理
subResult = cartographic3.Clone();
break;
case CoordinateType.Cartesian:
// 如果源是笛卡尔坐标
// 处理方法：
// 1.高斯正算,转为笛卡尔坐标系
GaussKrugerTransformation gauss_source_1 = new GaussKrugerTransformation(sourceEllipsoid);
cartesian3 = gauss_source_1.GaussKrugerForward(cartographic3, sourceCenterMeridian);
subResult = cartesian3.Clone();
break;
case CoordinateType.Projection:
// 如果源是投影坐标
// 处理方法：
// 1.高斯正算,转为笛卡尔坐标系
// 2.笛卡尔坐标转投影坐标
GaussKrugerTransformation gauss_source_2 = new GaussKrugerTransformation(sourceEllipsoid);
cartesian3 = gauss_source_2.GaussKrugerForward(cartographic3, sourceCenterMeridian);
projection = gauss_source_2.CartesianToProjection(cartesian3);
subResult = projection.Clone();
break;
default:
break;
}
result.Add(subResult);
}
return(result);
}
