Abstract:
Coordinate system is very important to determine positions on the surfaces, for example ground coordinate system depends on the earth surface. It can be change depends on several factors, the most important is earth crust move and earth quake, to avoid this reasons must be observe some of control points in different epochs to compare between epochs.
This research aims to compare between three epochs (2000-2005-2007) , by observed 30 points distributed in Khartoum state , the method for observation were static GPS observation , Root Mean Square Error(RMSE) was used for comparison between epochs.
