标签：beijing htm ted 地球 接口 arcgis war cal direction
转自：https://www.cnblogs.com/lonelyxmas/p/5784699.html
同一基准面的坐标转换
对于同一基准面，我们可以肯定一点就是同一位置经纬度坐标是一样的，而不同的就是计算成平面坐标的时候可能有所不同，因为算法不一样，在这里我只是将经纬度坐标转成平面的坐标。
private IPoint GetpProjectPoint(IPoint pPoint, bool pBool)
{
ISpatialReferenceFactory pSpatialReferenceEnvironemnt = new SpatialReferenceEnvironment();
ISpatialReference pFromSpatialReference = pSpatialReferenceEnvironemnt.CreateGeographicCoordinateSystem((int)esriSRGeoCS3Type .esriSRGeoCS_Xian1980);//西安80
ISpatialReference pToSpatialReference = pSpatialReferenceEnvironemnt.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type .esriSRProjCS_Xian1980_3_Degree_GK_Zone_34);//西安80
if (pBool == true)//球面转平面
{
Geometry pGeo = (IGeometry)pPoint;
pGeo.SpatialReference = pFromSpatialReference;
pGeo.Project(pToSpatialReference);
return pPoint;
}
else //平面转球面
{
IGeometry pGeo = (IGeometry)pPoint;
pGeo.SpatialReference = pToSpatialReference;
pGeo.Project(pFromSpatialReference);
return pPoint;
}
}
不同基准面的坐标转换
通过前面的介绍，我们知道地球上同一位置的坐标在不同的基准面上是不一样的，而基准面是构成坐标系的一个部分，因为基准面在定位的时候牵扯到了相对地心的平移或旋转等，所以对于这样的转换我们无法直接进行，需要一个转换参数，而这些参数也是基于不同的模型的，常用的有三参数和 7 参数,三参数是比较简单的也是比较容易理解的，三参数是在两个基准面之间进行了 X,Y,Z 轴的平移，通过下面的图我们很清楚的看到三参数之间两个基准面的关系：
而 7 参数的模型比较复杂，这种复杂的同时让精度大为提高，7参数不仅仅考虑了两个基准面之间的平移，还考虑了旋转外加一个比例因子(椭球体的大小可能不一样).
对于不同基准面之间的转换，ArcGIS Engine 提供了一个用来控制转换参数的接口 IGeoTransformation，该接口被以下类实现；
着每一个接口对应了一种转换方法，比如 GeocentricTranslationClass类就实现了三参数，而CoordinateFrameTransformationClass 类实现了7 参数，要实现 3 参数或者 7 参数需要 IGeometry2 或更新接口的ProjectEx 方法，下面我们用代码实现一个不同基准面之间的坐标转换。
public void ProjectExExample() { ISpatialReferenceFactory pSpatialReferenceFactory = new SpatialReferenceEnvironmentClass(); // ISpatialReference pFromCustom = pSpatialReferenceFactory.CreateESRISpatialReferenceFromPRJFile(@"E:\arcgis\Engine\z idingyi.prj"); IPoint pFromPoint = new PointClass(); pFromPoint.X = 518950.788; pFromPoint.Y = 4335923.97; IZAware pZAware = pFromPoint as IZAware; pZAware.ZAware = true; pFromPoint.Z = 958.4791; // ((IGeometry)pFromPoint).SpatialReference = pFromCustom; //自定义投影WGS84下的北京6度19带。 ((IGeometry)pFromPoint).SpatialReference = CreateCustomProjectedCoordinateSystem(); //目标投影 IProjectedCoordinateSystem projectedCoordinateSystem = pSpatialReferenceFactory.CreateProjectedCoordinateSystem((int)esriSRProjCS4Type.esr iSRProjCS_Xian1980_GK_Zone_19); //因为目标基准面和原始基准面不在同一个上，所以牵扯到参数转换，我用7参数 转换 ICoordinateFrameTransformation pCoordinateFrameTransformation = new CoordinateFrameTransformationClass(); pCoordinateFrameTransformation.PutParameters(-112.117, 4.530, 21.89, -0.00058702, -0.00476421, 0.00009358, 0.99998006411); pCoordinateFrameTransformation.PutSpatialReferences(CreateCustomProjectedCoordinate System(), projectedCoordinateSystem as ISpatialReference); //投影转换 IGeometry2 pGeometry = pFromPoint as IGeometry2; pGeometry.ProjectEx(projectedCoordinateSystem as ISpatialReference, esriTransformDirection.esriTransformForward, pCoordinateFrameTransformation, false, 0, 0); } private IProjectedCoordinateSystem CreateCustomProjectedCoordinateSystem() { ISpatialReferenceFactory2 pSpatialReferenceFactory = new SpatialReferenceEnvironmentClass(); IProjectionGEN pProjection = pSpatialReferenceFactory.CreateProjection((int) esriSRProjectionType.esriSRProjection_GaussKruger) as IProjectionGEN;IGeographicCoordinateSystem pGeographicCoordinateSystem = pSpatialReferenceFactory.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984); ILinearUnit pUnit = pSpatialReferenceFactory.CreateUnit((int)esriSRUnitType.esriSRUnit_Meter) as ILinearUnit; IParameter[] pParameters = pProjection.GetDefaultParameters(); IProjectedCoordinateSystemEdit pProjectedCoordinateSystemEdit = new ProjectedCoordinateSystemClass(); object pName = "WGS-BeiJing1954"; object pAlias = "WGS-BeiJing1954"; object pAbbreviation = "WGS-BeiJing1954"; object pRemarks = "WGS-BeiJing1954"; object pUsage = "Calculate Meter From lat and lon"; object pGeographicCoordinateSystemObject = pGeographicCoordinateSystem as object; object pUnitObject = pUnit as object; object pProjectionObject = pProjection as object; object pParametersObject = pParameters as object; pProjectedCoordinateSystemEdit.Define(ref pName, ref pAlias, ref pAbbreviation, ref pRemarks, ref pUsage, ref pGeographicCoordinateSystemObject, ref pUnitObject,ref pProjectionObject, ref pParametersObject); IProjectedCoordinateSystem5 pProjectedCoordinateSystem = pProjectedCoordinateSystemEdit as IProjectedCoordinateSystem5; pProjectedCoordinateSystem.FalseEasting = 500000; pProjectedCoordinateSystem.LatitudeOfOrigin = 0; pProjectedCoordinateSystem.set_CentralMeridian(true,111); pProjectedCoordinateSystem.ScaleFactor=1; pProjectedCoordinateSystem.FalseNorthing=0; return pProjectedCoordinateSystem; }
标签：beijing htm ted 地球 接口 arcgis war cal direction
原文地址：https://www.cnblogs.com/leebokeyuan/p/11613124.html
