Raster cell size

[johnpolo]

I have land use data from U.S.D.A. geospatial data gateway. I believe I read somewhere that the raster cell size is 30 m x 30 m. When I look in the Properties > Source > Raster Information, it says "Cell Size (X, Y)  31.871 , 31.871", I'm assuming that's in meters. I am trying to figure out approximate areas for several subsets of my map and want as close an estimate as possible. Can I consider it safe to do the math based on the 31.871 value and not 30?

[ChrisDonohue__GISP · Accepted solution]

I'd go with the 31.871 value over a general value of 30.

Also, to be on the safe side, it would be best to check the linear unit information for the image to confirm that it is meters.

In ArcMap, Right-click on the image in the Table of Contents, Properties, Source Tab, scroll down to the Spatial Reference subheading, then look at "Linear Unit" and see what the units are.

Chris Donohue, GISP

[johnpolo]

Thanks, Chris. That all helped.