Altimeter Verification
4
H|0|alt|altimeter|22|30|
H|0|process|measurement made by TOPEX/Poseidon|128|161|
H|0|sc|spacecraft|63|72|
G|0|accuracy|accuracy|112|119|
    TOPEX/Poseidon's altimeter measures the distance from the spacecraft to the ocean's surface. To verify the accuracy of the measurement made by TOPEX/Poseidon, the Precision Orbit Determination and Verification Team has a second, earth-based way of obtaining the altimeter-to-ocean distance. 
    This measurement comes from sea-level monitoring instruments placed on Texaco's Platform Harvest, an oil production platform located off the coast of California. The site was chosen so that land interference would not corrupt the altimeter return signal. 
    Measurements from the instruments on Platform Harvest are compared with those taken by TOPEX/Poseidon, to ensure that the spacecraft's altimeter is functioning properly and returning accurate measurements. 
