使用开源桌面GIS软件（uDig）进行投影变换

Changing the projection of a shapefile

In general uDig lets you work with shapefiles of different projections all on the same screen together. If you need to save a shapefile out in a specific projection for another application please use the following procedure.
Select the contents of your shapefile in the Catalog view; or by selecting a Layer if you have the shapefile on screen.
Open the Export wizard and choose Resource to Shapefile and press Next>
Chose a destination directory for your new shapefile:
C:/Documents and Settings/Jody/Desktop/data
Ensure your shapefile is checked off on in the list
Click on the current projection, example GCS_EGS1984, to open up a CRS chooser
Type in the name of the desired projection, example UTM zone 12N, and select the desired EPSG code from the list. You can confirm the details by looking at the Custom CRS tab
Press Finish, your newly created shapefile is available in the Catalog view


上面的内容是uDig的帮助文档里面的内容，翻译过来就是：
在Catalog View里面选中所要转换的文件。
打开右键菜单，选择Export...，在弹出的对话框中选中Resource to Shapefile
选择新文件的存放位置，如C:/data
点击现有的投影，如GCS_EGS1984，在弹出的对话框中选择想要的投影，如WGS 84（ESPG: 4326）
点击Finish，即可完成投影的转换，新文件即为有新坐标系的文件