topic Re: Extract by Mask in ArcGIS Spatial Analyst Questions

Extract by Mask

RobertWilliams3 — Tue, 08 Nov 2016 21:55:40 GMT

Hi folks,

I've been standardising raster layers (climate data) using the 'Extract by Mask' tool and my template raster. However, I have one layer that produces a raster with seemingly no data associated. I had successfully processed this layer with the extraction previously, but when I tried to redo having specified an incorrect coordinate system the 'Extract' no longer returns values. Help much appreciated

Thaks

Re: Extract by Mask

DarrenWiens2 — Tue, 08 Nov 2016 22:02:25 GMT

Are you trying to overwrite the old file or start with a new file? Delete the old file, start from scratch, get everything into the correct CRS, and try again.

Re: Extract by Mask

RobertWilliams3 — Tue, 08 Nov 2016 22:07:13 GMT

Thanks for the reply Darren.

I've tried starting from scratch with the original data layer having deleted all previous attempts. Same thing every time. Any other thoughts?

cheers

Re: Extract by Mask

DarrenWiens2 — Tue, 08 Nov 2016 22:16:35 GMT

Okay, it sounds like everything (both data layers and the data frame) is in the same CRS and it overlaps on the screen. Check the extent and mask environment just to be sure it hasn't been set to some other part of the world. Other than that, try restarting ArcGIS. Finally, try going for a coffee and coming back later (sometimes it helps ).

It does sound like you've got a handle it, though, since you've done several of these already. Is this case different in some way, other than the first time around used the wrong CRS?

Re: Extract by Mask

RobertWilliams3 — Tue, 08 Nov 2016 22:32:56 GMT

Yeh, I've processed around 10 of these in preparation for use in MAXENT. I can see nothing different with this layer prior to the extraction or in the mask environment. The mask is only being used to reduce the extent and cell size to that of the template, as the original input already has the desired CRS. ARCMap does seem to have been struggling today and crashed on the last attempt. Which brings me here Is it possible that Arcmap is just having a fit?