Satellite Radar Altimeter Accuracy

Satellite radar altimeters measure the ocean surface height sea level by measuring the time it takes a radar pulse to make a round trip from the satellite to the sea surface and back.

Satellite radar altimeter accuracy.

A satellite radar altimeter is a nadir looking radar with very high range resolution which measures the ocean surface topography with an accuracy in the order of few centimeters. Abstract the unprecedented accuracy of elevations retrieved from the ice cloud and land elevation satellite icesat laser altimeter is investigated and used to characterize the range errors in the environmental satellite envisat and european remote sensing 2 satellite ers 2 radar altimeters over the continental ice sheets. The poseidon 3 altimeter emits pulses at two frequencies 13 6 and 5 3 ghz to measure the distance from the satellite to the surface range. Launched in 1992 as a joint mission of the american and french space agencies and still operating as of 2001 t p is the most accurate altimeter flown to date.

A radar altimeter ra radio altimeter ralt electronic altimeter or reflection altimeter measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground reflect and return to the craft. Its microwave radars measure the distance to the sea surface with a precision of 2 cm. Bathymetry is measurement of the depth of the ocean. Additionally analysis of the echo amplitude and shape can extract information about the wind speed and wave height respectively.

Figure 1 shows a schematic of the topex poseidon t p satellite altimeter system. Satellite altimeter radar measurements can be combined with precisely known spacecraft orbits to measure sea level on a global basis with unprecedented accuracy. This type of altimeter provides the distance between the antenna and the ground directly below it in contrast to a. An altimeter measures how high something is.