Microsoft's Mark Brown has put up a cool post on his Microsoft Virtual Earth blog. It's part two of a series that's detailing some of the bits and pieces behind the tool that gives you that oh-so-helpful bird's-eye view of your dry cleaners.
In this episode Brown sits down with Keystone Aerial Surveys, a Philadelphia-based company that's got less than 50 employees and 14 airplanes doing all the capture work.
- Keystone's flights average about 5 hours a trip.
- Each trip brings in about 1,000 super high-resolution images that come out to about 100 square miles.
- Certain map suppliers will only shoot during certain parts of the year--Microsoft takes photos year round.
- City images can be some of the toughest shots to get because of shadows.
- Companies like Keystone need to buddy up to air traffic controllers to get special clearance for "loitering" (going back and forth in the same general area).
- Pilots get their flight data from software that maps out areas that need to get captured. You can see a demo of this in action in the first third of the video.
- The "UltraCam" that takes the pictures uses a special infrared sensor that cuts through cloudy spots. You can see it snapping and cutting apart shots once they're up in the air.
The video is a about an hour long and definitely worth a watch if you like planes and maps. If you're feeling impatient you can skip ahead to the 32:10 mark to get to the good stuff--like when they're flying around to take pictures of your backyard.
Behind The Maps - Flying the UltraCam
Note: I didn't even realize until after posting that the video was in Silverlight and not Adobe Flash, so if you absolutely refuse to download and install it on your system there are alternate download links courtesy of XBOX Live's Major Nelson: iPod, Zune, PSP and WMV