Spatial extent

The spatial extent is the allowable range for x and y coordinates (and for m and z values if you have them). When you create a feature class or feature dataset, the spatial extent is defined using minimum and maximum x and y coordinate values.

The minimum and maximum x,y coordinates are determined by the bottom left and top right corners of the bounding rectangle.

When you're creating a feature class or feature dataset, ArcCatalog will always provide you with either placeholder values or default values for the spatial extent.

· If you select a predefined coordinate system or create a new one, the values shown for the spatial extent are merely placeholders which you will need to modify.

· If you import the spatial reference from another geodatabase feature class or feature dataset, the minimum and maximum x and y coordinate values are the same as the source data.

· If you import the spatial reference from a shapefile or coverage, ArcCatalog provides default values for the spatial extent which it calculates by adding a buffer to the source data extent. The buffer is a perfectly square area that is some multiple of the larger side of the source data's extent (up to 10 times its width or height) and is centered around the source data extent. This buffer allows room for your data to expand.

For example, when creating a feature dataset, if you import the spatial reference for Germany from Germany.shp and later decide you want to add the rest of Europe to your feature dataset, you will have plenty of room to do so.

The default spatial extent for a feature dataset as calculated by ArcCatalog.

Once a new feature class or feature dataset has been created, you cannot change its spatial extent!