标签：
GeoTools是在java下的gis开源软件，以下介绍坐标转换的两种方法：投影转换和仿射变换
这里以xian80经纬度坐标转xian80，3度分带 111中央经线平面坐标为例
转换函数如下：
1 Point pointXian80 = projectTransform(lon, lat, "EPSG:4610", "EPSG:2382");
1 /** 2 * 投影转换， lon=经度，lat=纬度，ESPG格式（例）：EPSG:4610 3 */ 4 public static Point projectTransform(double lon, double lat, 5 String epsgSource, String epsgTarget) throws FactoryException, 6 MismatchedDimensionException, TransformException { 7 // 原始坐标点 8 // PS:通常逻辑上理解经度应该是横坐标x，纬度是y，可是这里经度要填到y，纬度x，否则会报错 9 Point sourcePoint = JtsHelper.createPoint(lat, lon); 10 11 // 定义转换前和转换后的投影，可以用ESPG或者wkt 12 // "PROJCS[\"Xian_1980_3_Degree_GK_CM_111E\",GEOGCS[\"GCS_Xian_1980\",DATUM[\"D_Xian_1980\",SPHEROID[\"Xian_1980\",6378140.0,298.257]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Gauss_Kruger\"],PARAMETER[\"False_Easting\",500000.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",111.0],PARAMETER[\"Scale_Factor\",1.0],PARAMETER[\"Latitude_Of_Origin\",0.0],UNIT[\"Meter\",1.0]]"; 13 // CoordinateReferenceSystem mercatroCRS = CRS.parseWKT(strWKTMercator); 14 CoordinateReferenceSystem crsSource = CRS.decode(epsgSource); 15 CoordinateReferenceSystem crsTarget = CRS.decode(epsgTarget); 16 // 投影转换 17 MathTransform transform = CRS.findMathTransform(crsSource, crsTarget); 18 Point pointTarget = (Point) JTS.transform(sourcePoint, transform); 19 20 return pointTarget; 21 }
关于定义坐标系的说明，GeoTools中定义坐标系有两种方法，一是坐标系的wkt，二是ESPG
坐标系的wkt可以从arcgis的prj文件中过去，用记事本打开prj文件，里面的内容就是该坐标系的wkt格式内容，例如：PROJCS[\"Xian_1980_3_Degree_GK_CM_111E\",GEOGCS[\"GCS_Xian_1980\",DATUM[\"D_Xian_1980\",SPHEROID[\"Xian_1980\",6378140.0,298.257]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Gauss_Kruger\"],PARAMETER[\"False_Easting\",500000.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",111.0],PARAMETER[\"Scale_Factor\",1.0],PARAMETER[\"Latitude_Of_Origin\",0.0],UNIT[\"Meter\",1.0]]
获取到wkt后，可以通过 CoordinateReferenceSystem mercatroCRS = CRS.parseWKT(strWKTMercator); 获取到坐标系对象
另一种方法是ESPG，意思是每一个坐标系都有一个ESPG标准的号码，查询坐标系的ESPG可通过以下网站 http://spatialreference.org/
PS：当转换的两种坐标系的datum不同，会报错Bursa-Wolf parameters，暂时未解决
代码如下：
首先是输入三组参考点，前三个是转换前，后三个是转换后
最后结果是pointReuslt
1 // 参考点坐标 2 Coordinate s1 = new Coordinate(429275.549, 2801455.153); 3 Coordinate s2 = new Coordinate(428110.626, 2792148.620); 4 Coordinate s3 = new Coordinate(428966.479, 2800016.622); 5 6 Coordinate t1 = new Coordinate(4628.339, 801349.338); 7 Coordinate t2 = new Coordinate(3515.906, 792036.308); 8 Coordinate t3 = new Coordinate(4327.381, 799909.069); 9 // 建立仿射变换对象 10 AffineTransformationBuilder afb = new AffineTransformationBuilder(s1, 11 s2, s3, t1, t2, t3); 12 AffineTransformation atf = afb.getTransformation(); 13 14 Point pointReuslt = JtsHelper.createPoint(x,y); 15 16 // 坐标转换 17 pointReuslt.apply(atf);
标签：
原文地址：http://www.cnblogs.com/cannel/p/5323925.html
