laser altimeter

[′lā·zər al¦tim·əd·ər]

(navigation)

An altimeter in which a laser beam, modulated by radio frequencies, is directed downward from an aircraft, and the laser light reflected from the terrain is picked up by a telescope system, sensed by a photomultiplier, and phase-compared with the transmitted signal to obtain the round-trip propagation time; the height above ground equals one-half the product of the propagation time and the speed of light.

laser altimeter

An altimeter that measures the time it takes for a laser pulse to return from the ground directly below the aircraft. This time is converted into height above the ground, and this is what the altimeter indicates. It is more accurate than a radio or radar altimeter. A laser altimeter measures and indicates absolute altitude.

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References in periodicals archive

LAM (laser altimeter) deployed on CE-1 obtained about total 9.12 million measurements covering the whole lunar surface.

A New Lunar DEM Based on the Calibrated Chang'E-1 Laser Altimeter Data

Optimization of an airborne laser altimeter for remote sensing of vegetation and tree canopies.

Lidar remote sensing for forestry and terrestrial applications

An earlier report, based on laser altimeter data, said there was obvious evidence that there once were oceans of surface water on Mars.

US probe may have found water on surface of Mars

Planetary scientists are moving closer to an understanding of Martian water thanks to the Mars Orbiter laser altimeter. The altimeter, an instrument on the Global Surveyor satellite, helps scientists map the topography (physical features) of Mars' surface by measuring the altitude (height) of landforms (see SW 9/20/99, p.

MISSION to MARS

This paper reviews the application of an airborne laser altimeter for measuring vertical features and patterns of the landscape surface at Walnut Gulch Watershed.

Laser altimeter measurements at Walnut Gulch Watershed, Arizona

More specifically, the UK's Ministry of Defense describes the program's objectives as being the creation of a system capable of "detecting obstacles, terrain following, true air-speed measurement and ground air target characterization." Work to date includes French avionics contractor Sextant testing a laser air-speed measurement system aboard a Mirage III testbed aircraft and the UK's Thorn EMI working on laser altimeter and helicopter obstacle warning systems.

Desert Storm - first non-US perspective

This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations now that the spacecraft is in proximity to Bennu.

Water Discovered On Asteroid Bennu

New observations of Mercury's northern polar regions come from MESSENGER's laser altimeter, which maps the planet's topography and measures how reflective the surface is.

First rock from the sun has ice: Mercury's water probably came on asteroids or comets

The spacecraft has a camera to make wide and narrow angle images of Mars, and a laser altimeter to measure the height and depth of surface features by bouncing pulses of light off the planet.

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