queries and classification of raster data

drm

Hi. My use of GM has mostly been making simple raster-based measurements and I'm wondering if it has the capabilities to do some vector-based analysis that I'm unfamiliar with.

Specifically, I have made airborne maps of snow depth at 25 cm postings over 1000s of square kilometers and what I would like to do is impose a 5 km x 5 km grid over this to interrogate the snow depths within each of those 5km grid cells, answering questions such as "do more than 10% of pixels within this grid cell have less than 6" of thickness"? Then I'd like to color those 5km grid cells by the answer (say green for Yes and red for No) and create a new raster map at 5 km posting over those 1000s of square kilometers.

Is this possible?

Thanks!

Matt