How to Change 90 m DEM raster to 250 m resolution?

[AlperOnen]

Hello, first of all, sorry if this is a pretty basic thing to do. I searched over internet for a while but couldn't find a direct explanation.

I have downloaded some 90 m DEM files from USGS and merged them on ArcGIS and I want to convert the merged DEM into 250 m resolution. I think I have to use Raster Calculator but since I'm not familiar with it, I need some assistance.

Thanks in advance.

Al

[MelitaKennedy]

Perhaps the Resample Tool in Data Management, Raster toolset, Raster processing toolset is what you're looking for.

Melita

[AlperOnen]

Oh guess that does the trick. Thank you. About the cell size, 90 m DEM data has a cell size of 8.3333E-04, to convert it to 250 m, should I calculate it with direct ratio (8.3333E-4 x 250 m / 90 m) or should I do somewhat a scaling adjustment other than this?

[EricRice · Accepted solution]

Hi Al,

It sounds like you have SRTM 90 m data, which typically comes in a geographic coordinate system (WGS_1984) having a resolution of 0.00083333333 decimal degrees.  If you truly want your data to have units of meters you need to run Project Raster and specify a coordinate system that uses meters.  Then you specify 250 for output cell size.  Please be sure to set your resampling technique in the tool to Bilinear since the default is Nearest (which you don't want).

Best Regards,
Eric

[AlperOnen]

Thank you very much :).