ICESat Data Accumulation Animation

Accumulating Data: Glas Builds Its Facts One Point at a Time - The technology behind GLAS is called lidar. Lidar is a distance measuring system similar to radar, except that instead of radio waves it uses pulses of laser light for range finding. The name is a contraction based on the words light and radar: Light Detection And Ranging. A lidar system determines precise distances by measuring the amount of time necessary for a pulse of light to leave an emitter, hit a target, and return. In this case, distance measurements helped researchers determine changes in ice thickness, vegetation, cloud thickness, and much more.