I have a shape file. The coordinates (Lat/Long) are projected as meter (555000, 155000). But, I want to re-project it to decimal degrees(51.523666, -0.07467). How can I do it with ArcMap or Quantum GIS?
Thanks, In advance
In QGIS, it's very straightforward. First, ensure that you have the correct coordinate system for your original shapefile:
It's a very good idea to make sure you select a good name in the "Save as" dialog - appending the coordinate system to the name can be very helpful, e.g. my_shape_file_DD_WGS84 to remember that it's in degrees, WGS84.
You will need to know the coordinate system of the projected data and then change it base to decimal degrees using the Project tool in the data management toolset if you want to do it in ArcMap. The define projection tool can be used to establish a coordinate system for the input file if it is unknown.