Have you tried the following? Set your Analysis window extent (Spatial Analyst Toolbar/Options/Extent/) to the raster layer with the largest extent and use the calculator to create new grids from your grids that have smaller extents. The areas outside the original extent of your smaller grids will now have no data values. If you need to change the no data values to perform calculations on all the grids, you can incorporate the isnull command with a Con statement. If you need help with that, let me know. Hope this helps,
Stefan -----Original Message----- From: Kevin Ramsey [mailto:[email protected]] Sent: Wednesday, December 16, 2009 10:42 AM To: UW - GIS Discussion & Support Subject: [UW-GIS-L] trick to expanding extent of raster data? Hello, I'm working with several raster layers in ArcMAP 9.3.1. The geographic extend of these layers differs. I'd like to change the extend of the smaller raster areas to match the larger ones so that my raster calculator procedures work correctly. This appears to be a simple a simple procedure. I've tried changing the geographic extent in the layer properties several times using different options ("the full extent of all layers", etc.). I then try to reclassify the raster so that all the "no data" cells are classified as "0". But the geographic extent of the data doesn't change when I do this. Do any of you know of a trick that I'm missing here? Thanks! Kevin -- -------------------------------------------------- Kevin Ramsey, Ph.D. Lecturer, Interdisciplinary Arts and Sciences, University of Washington Bothell http://staff.washington.edu/kramsey _______________________________________________ Uw-gis-l mailing list [email protected] http://mailman1.u.washington.edu/mailman/listinfo/uw-gis-l -------------------------------------------------------------------- All e-mail correspondence to and from this address are subject to the Washington State Public Records Act, which may result in monitoring and archiving, as well as disclosure to third parties upon request. _______________________________________________ Uw-gis-l mailing list [email protected] http://mailman1.u.washington.edu/mailman/listinfo/uw-gis-l
