An overview of coverage settings
The environment settings in the Coverage section of the Environment Settings dialog box apply to coverage tools only. The default values for the following settings can be changed: the precision for new or derived coverages and the level of comparison between projection files.
Level of comparison between projection files
Before running coverage tools, you can set the degree of similarity between input projection files required for a match to occur using the Level of comparison between projection files environment. Use this option if you want to validate the input projections before running coverage tools.
The following settings are available:
- NONE—No comparison of projection files is made. Any combination of projection information will result in a match. Tools will run regardless of the projection of the inputs. This is the default.
- PARTIAL—At least one projection file must be defined; the others can be unknown and will result in a match. Defined projection files must be identical.
- FULL—All projection information must be specified and identical in the projection file of each input dataset.
Precision for coverages
Before you begin using tools in the Coverage Tools toolbox, you should determine what the precision of your output coverages should be.
New coverages are those that are created—for example, using the Create Coverage tool. Derived coverages are those that are derived from tools that accept input data to derive the output coverage—for example, coverages created by running the Buffer tool.
The default precision is set to SINGLE for new coverages that are created and HIGHEST for derived coverages. If you want new coverages that are created to be in double precision, set the Precision For New Coverages to DOUBLE. If you always want derived coverages to be in double precision, regardless of the precision of the input data, set the Precision For Derived Coverages to DOUBLE.