laser altimeter


Also found in: Acronyms.

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.
References in periodicals archive ?
LAM (laser altimeter) deployed on CE-1 obtained about total 9.12 million measurements covering the whole lunar surface.
Optimization of an airborne laser altimeter for remote sensing of vegetation and tree canopies.
An earlier report, based on laser altimeter data, said there was obvious evidence that there once were oceans of surface water on 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.
This paper reviews the application of an airborne laser altimeter for measuring vertical features and patterns of the landscape surface at Walnut Gulch Watershed.
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.
This instrument can be found on top of the lander so once it successfully makes a lunar landing, NASA's Lunar Reconnaissance Orbiter can launch a laser altimeter at it to pinpoint the Beresheet's location.
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.
ICESat-2 will carry a single instrument, the Advanced Topographic Laser Altimeter System (ATLAS), which will send 10,000 laser pulses a second to Earths surface and measure the height of ice sheets, glaciers, sea ice and vegetation by calculating the time it takes the pulses to return to the spacecraft.
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.
MARYLAND (CyHAN)- MESSENGER's Mercury Laser Altimeter sends out laser pulses that hit the ground and return to the instrument.
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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