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Grosskopf W. Aubrey D. Mattie M. Mathiesen M. 《Oceanic Engineering, IEEE Journal of》1983,8(4):254-271
Five measurement strategies (four in situ, one remote) for estimating directional wave spectra were intercompared in a 1980 experiment at the Coastal Engineering Research Center's Field Research Facility in Duck, NC. The systems included two pressure sensor/biaxial current meter combinations (different manufacturers), a triaxial acoustic current meter, an SXY gauge (square array of four pressure sensors), and a shore-based imaging radar. A detailed error analysis suggests sources for differences in estimated wave spectra from the different instruments; in general, they intercompare favorably. The major deviation among in situ gauges was associated with the triaxial acoustic current meter. Reliance on a vertical velocity measurement (instead of a direct pressure or sea-surface elevation measurement) can contribute additional uncertainty in directional spectral estimates. The imaging radar was successful in distinguishing multiple wave trains at the same frequency, which was not possible with the simple spectral estimation analysis applied to in situ data. However, the radar is not useful in providing accurate estimates of spectral density, nor in distinguishing multiple wave trains of different frequencies coming from the same direction. Selection of a measurement strategy for a particular need depends on the precise data requirements for that application. Although the five tested intercompared well, in practice not all are equally suitable for every application. 相似文献
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During a March 1977 experiment, four systems were used to provide wave-direction information offshore of Mission Beach, CA: a synthetic aperature radar (SAR) carried aboard a NASA CV990 aircraft, a coastal imaging radar, a pressure-gauge array offshore, and aerial photography aboard two aircraft. The coastal radar, aerial photographs, and SAR provided wave images. From the coastal radar images and the aerial photographs, the direction and length of the principal wavetrains were measured by a manual analysis. The SAR images were also processed using an FFT to give two-dimensional wave spectra. The array at the Naval Ocean Systems Center (NOSC) tower was used to provide directional wave spectra. Scatter diagrams are presented, which intercompare the measurements from these four systems. In addition, radar image spectral information is compared with the array spectra. The intercomparison of the data from these four systems shows good agreement among the imaging systems. Between the imaging systems and the pressure array there is agreement for the most prominent wavetrains and disagreement for several cases where multiple wavetrains from different directions but with similar periods are present. 相似文献
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