I guess you could do some sort of selection on the raster based on the values of the 4 bands in the IR imagery. I've done something similar selecting out areas based on the values of one band in ArcMap years ago. I really thnk it's a job for a full fledged imagery analysis software like Imagine or ENVI, though. I don't know what its like now, but a few years ago ENVI was much less expensive than Imagine and is more than capable of handling what you need to do. Hopefully someone else with more raster experience can weigh in.

Barry

I work for a storm sewer utility and we bill according to the amount of impervious surface on a developed parcel. I recently acquired color and infrared imagery of my city. I would like to use that imagery to do a land cover analysis, specifically to delineate areas of impervious surface. I have a couple of questions.

1) Has anyone on this forum done such an analysis? What do I need to know I approach this? Where can I find some documentation about how to do it?

2) Can I do the analysis with ArcMap out of the box? If I need to purchase third party software, what should I get? ERDAS? IDRISI? Something else?

Any input would be appreciated.