topic Converting GRID from centimeters to meters in ArcGIS Spatial Analyst Questions

Converting GRID from centimeters to meters

DawnBaldridge — Mon, 20 Sep 2010 18:23:21 GMT

I am currently using 9.3.1 to convert a 16 bit signed GRID from centimeters to meters. I am using the raster calculator with the expression [GRID] * 0.01. When using that expression I get a floating point GRID...which I do not want. When I use the expression int([GRID] * 0.01) I get an 8 bit signed GRID. Does anyone know how I can get a 16 bit signed GRID like the original I am using? Thank you.

Re: Converting GRID from centimeters to meters

EricRice — Tue, 05 Oct 2010 19:50:53 GMT

Dawn,

In this unit conversion scenario your result is always going to be floating point values, unless all pixels evenly divide by 100 (since you technically could divide by 100 - not a float value).

When you do this operation you're actually decreasing the range of values in the raster. Storing 16 bits may not be necessary. What is the new range of values after multiplying by .01 and doing INT? What format are you working with? ESRI GRIDs are always 32 bit anyway...

Eric