The Comparison of Discus Buoy Wave Spectra Produced by Buoy-Fixed and Vertically Stabilized Accelerometers

Burdette, E.

doi:10.1109/oceans.1978.1151098

Cited by 6 publications

(1 citation statement)

References 7 publications

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“…Tucker (1956Tucker ( , 1959 was the first to recognize that the accuracy of wave measurements made with a strapped-down, 1D accelerometer could be different from those made with a vertically stabilized accelerometer. This is the approach taken by NDBC (Burdette 1978;Steele et al 1978;Steele and Earle 1979;Earle and Bush 1982;Earle et al 1984;Lang 1987;Bouchard et al 2009). The errors were comparable to the wave's spectral energy for frequencies less than 0.04 Hz, frequencies that were quite rare even for swell in the Pacific.…”

Section: A Noise Correction Filtermentioning

confidence: 99%

A Comparison of Methods for Determining Significant Wave Heights—Applied to a 3-m Discus Buoy during Hurricane Katrina

Bender

Guinasso

Walpert

et al. 2010

Journal of Atmospheric and Oceanic Technology

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In August 2005, the eye of Hurricane Katrina passed 90 km to the west of a 3-m discus buoy deployed in the Mississippi Sound and operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). The buoy motions were measured with a strapped-down, 6 degrees of freedom accelerometer, a three-axis magnetometer, and from the displacement of a GPS antenna measured by postprocessed-kinematic GPS.Recognizing that an accelerometer experiences a large offset due to gravity, the authors investigated four different means of computing wave heights. In the most widely used method for a buoy with a strapped-down, 1D accelerometer, wave heights are overestimated by 26% on average and up to 56% during the peak of the hurricane. In the second method, the component of gravity is removed from the deck relative z-axis accelerations, requiring pitch and roll information. This is most similar to the motion of the GPS antenna and reduces the overestimation to only 5% on average. In the third method, the orientation data are used to obtain a very accurate estimate of the vertical acceleration, reducing the overestimation of wave heights to 1%. The fourth method computes an estimate of the true earth-referenced vertical accelerations using the accelerations from all three axes but not the pitch and roll information. It underestimates the wave heights by 2.5%. The fifth method uses the acceleration from all three axes and the pitch and roll information to obtain the earth-referenced vertical acceleration of the buoy, the most accurate measure of the true wave vertical acceleration. The primary conclusion of this work is that the measured deck relative accelerations from a strapped-down, 1D accelerometer must be tilt corrected in environments of high wave heights.

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