Geographic Information Systems - sort of Google Maps on steroids. GIS is typically built and maintained at the town, city or county level and is much more than a satellite view of your locality. Very simply, and for most of our uses, through the use of overlays, you can identify such things as government buildings, property lines, bodies of water, street names, etc... or you can remove all of those things and just have the satellite view. It can be good for determining population densities, alternate routes, water sources that might not be obvious from the road, and where nearby property lines might be. For some of us in rural areas, we might not know that if we go through our woods, and cut across the neighbor's back 40, we'd come across a stream fed pond that has a narrow dirt road leading to it (or some other useful information).
Many municipalities keep the GIS information for internal use, or make it difficult to get to. But others put it right out there for us, the folks who paid for it, to use at will.
Here's a couple of quick specifics for ways that GIS could be a handy tool for us:
- OPSEC Maps - You can set up maps of your AO (Area of Operations), but remove all indicators of road names, grid coordinates, and property names
- Water Sources - nearby streams, ponds and even rivers that you may not know about how close they really are
- If you are skilled with computer graphics, you can use the GIS overheads of your property and identify defensive locations, natural perimeter markers, distances to various features, and interlocking fields of fire