LIDAR

http://www.extension.org/pages/9689/lidar-derived-products#.Uoq6tqVgzRY

LIDAR, or Light Detection and Ranging, is an optical remote sensing technology that uses light to detect distances to an object and other properties of that target. This is done using pulses from a laser. LIDAR has applications in the fields of physics, geology, the military, geography and archeology among many other fields. Flood risk assessments have been increasingly using LIDAR as well because of the highly accurate landscape and elevation characteristics LIDAR provides as such in the picture above.