Abstract: Light Detection and Ranging, or lidars, are similar to radars but at optical wavelengths. They have the unique advantages of high temporal and spatial resolution and high measurement efficiency because of the much shorter wavelengths. Lidars have been used to map Mars, Mercury, and the Moon, with unprecedented precision and accuracy. There have been several Earth orbiting lidar missions which measured the surface elevation, atmosphere backscattering profiles, and vegetation coverage. Several …