A mask is set in the General tab of the Options dialog box of Spatial Analyst. The Contour or Kriging function is run on a dataset that has a larger extent than the mask. The output dataset has the same extent as the input, not of the mask, as was intended.
This is a known issue with ArcGIS 8.1.
The Contour and Kriging functions of Spatial Analyst do not respect the Mask set in ArcGIS 8.1.
Solution or Workaround
- For the Kriging operation:
1. Run a “relation equal to” operation in the Raster Calculator with the output from the Kriging function.
2. Enter the output raster layer into the Raster Calculator:
This will yield a final raster with the same extent as the mask.
- For the Contour operation:
1. Clip the data to be contoured by using a “relation equal to” operation in the Raster Calculator.
2. Type the layer to be clipped to the mask in the Raster Calculator:
3. Use the resulting raster in the Contour function. The final result will be a dataset with the same extent as the mask.