This site allows us to look at lidar data. This is a radar-like form of digital imaging where the earth's surface is modeled from flying overhead. The raw lidar model shows houses, bushes, etc. Anything that reflects radar. The data is filtered to make a bare-earth model. In general, anything that shows up on the bare earth model makes the surface to rough to race on. Unfortunately, the radar does not look under water so Lake Tahoe looks like a nice and flat playa.
The lidar data can be merged with all sorts of other useful Global Positioning System (GPS) data to locate prospective playas. It can take about half an hour to make a good model showing the area of the desert that is worthy of further investigation. Of course, we want to download and save the file for future use. At my job they have a nice big server to store the stuff. The files are ginormous and they will bring a home PC to its knees. I have had major problems with my home 'puter and it took me weeks to figure out what is happening. There are ways to streamline the files but they must be downloaded first. The problem is that it is hard to truly delete something from a PC. They go to recycling bins or trash can files. This week I am taking a class on it.
Anyway, showing you'all how to use this GPS site and not overload your computer is too much for my non-nurdley abilities. Go look at the stuff and mess around with it. Just be careful and do not download anything unless you know what you are doing.