Satellite Radar Altimeter

Combining the physical explanation of the function fitting and the high adaptability of empirical statistical methods we effort to provide a comprehensive method for processing the waveforms over the open ocean and coastal area.

Satellite radar altimeter.

Operating at 13 6 or 35 75 ghz each altimeter emits a series of microwave pulses towards the surface. Poseidon 2 operates at two frequencies 13 6 ghz in the ku band 5 3 ghz in the c band to determine atmospheric electron content which affects the radar signal path delay. Hence ocean viewing altimeters have a small range window whose position tracks the delay and strength of the surface reflection. Waveform retracking for precise sea surface height ssh is an important method to improve the quality of satellite altimeter data.

The altimeter emits a radar beam that is reflected back to the antenna from the earth s surface. 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. Bathymetry is measurement of the depth of the ocean. Surface height is the difference between the satellite s position on orbit with respect to an arbitrary reference surface the earth s centre or a rough approximation of the earth s surface.

Satellite radar altimetry measures the time taken by a radar pulse to travel from the satellite antenna to the surface and back to the satellite receiver. This measurement yields a wealth of information that can be used for a wide range of applications in particular for understanding sea level rise. A satellite based radar altimeter needs to measure the distance accurately but only for an essentially planar surface oriented orthogonally to the radar s line of sight. The reference ellipsoid and the satellite to surface range calculated by.

This measurement is performed through the recording of the pulse bounced back by the reflecting facets within the altimeter footprint. Radar altimetry measures the two way travel time of a radar pulse between the satellite antenna and the earth s surface at the nadir of the spacecraft. An altimeter measures how high something is. The principle is that the altimeter emits a radar wave and analyses the return signal that bounces off the surface.