Small Lidar Altimeter Would Operate at Low Light Levels

A lidar apparatus called a microaltimeter has been proposed for use aboard a spacecraft in orbit around the Earth for mapping land and sea surfaces, including such features of special interest as ice, tree canopies, and flood plains. The microaltimeter is short for "microlaser altimeter" and is so named because it uses a very compact, low-energy, subnanosecond pulse, solid-state microlaser as its source and relatively small (typically 10 to 20 cm in diameter) telescopes, resulting in a factor of 100 reduction in telescope weight and volume, as compared to conventional spaceborne laser altimeters. Operating at thousands of pulses per second, the surface sampling rate is approximately 100 times higher than that of prior spaceborne laser altimeters having the same transmitter power-aperture product.