CODAR, a high-frequency (HF) compact radar system, was operated continuously over several weeks aboard the semisubmersible oil platform Treasure Saga for the purpose of wave-height directional measurement and comparison. During North Sea winter storm conditions, the system operated at two different frequencies, depending on the sea state. Wave data are extracted from the second-order backscatter Doppler spectrum produced by nonlinearities in the hydrodynamic wave/wave and electromagnetic wave/scatter interactions. Because the floating oil rig itself moves in response to long waves, a technique has been developed and successfully demonstrated to eliminate to second order the resulting phase-modulation contamination of the echo, using separate accelerometer measurement of the platform's lateral motions. CODAR wave height, mean direction, and period are compared with data from a Norwegian directional wave buoy; in storm seas with wave heights that exceeded 9 m, the two height measurements agreed to within 20 cm RMS, and the mean direction to better than 15 degrees RMS.
CODAR wave measurements from a North Sea semisubmersible
CODAR Wellenmessungen einer halbgetauchten Nordsee-Plattform
IEEE Journal of Oceanic Engineering ; 15 , 2 ; 119-125
1990
7 Seiten, 15 Quellen
Article (Journal)
English
Online Contents | 2002
Online Contents | 2002
CODAR operations in the straits of Florida
Tema Archive | 1986
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