I have a problem displaying two topographic maps. They both have the same projection system and the same scale and show the same section of the landscape. However, when I load them into ArcGIS (9.3) they don´t match each other in size. While one map is situated correctly, the other one is displayed in a bigger scale. How I said before, scale and projection are the same. Has anybody some idea? One of the layers probably has the wrong coordinate system defined for it. There are a few ways to figure out which one is correct. 2. In ArcMap, change the display units (data frame properties, general tab) to decimal degrees. Do the values make sense for the location the layers represent? If the data are in the US, could one be using units of feet versus meters? Or UTM versus State Plane? Or is one using a geographic coordinate system (decimal degrees, latitude/longitude)? Hello and thank you for your helpful hints. We now had a deeper look to the properties of the two raster datasets and discovered, that they have a different cell size. While one has a cell size of 1×1 meters, the other dataset has a cell size of 0.5×0.5 meters. Do you know how to change the cell size of a raster? We tried in the properties table, but we´re not allowed to change it there. Is there a special tool for changing the cell size of a raster? I have an analyst having a similar problem he has a workflow he runs creating rasters. In 9.2 he gets one cell size but in 9.3 he gets a much larger cell size. He just down graded to 9.2 and he is now getting the smaller cell sizes again? Source.