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Sea surface flow estimation from advanced very high resolution radiometer and coastal zone color scanner satellite imagery: A verification study

1988; American Geophysical Union; Volume: 93; Issue: C6 Linguagem: Inglês

10.1029/jc093ic06p06735

2156-2202

Jan Svejkovsky,

Underwater Acoustics Research

A refined technique for estimating surface currents from the displacement of features in sequential advanced very high resolution radiometer (AVHRR) and coastal zone color scanner (CZCS) images is presented. It is used to calculate flow fields in two regions along the California coast, and the results are compared to concurrent drifter drogue observations. There is overall agreement to within approximately 6 cm/s, with somewhat better agreement at velocities less than 40 cm/s. The poorer performance of the technique at high velocities was due to difficulties in identifying and tracking features in areas of rapid flow. The accuracy of the measurements is primarily affected by the analyst's precision in tracking each feature which, in turn, depends on how well the 2‐ to 6‐km features preserve their identity from one image to the next. A 12‐ to 24‐hour interval yielded the best results in this study. The directional component of the satellite‐derived flow field was representative of subsurface flow patterns down to at least 100 m. Although velocities obtained from AVHRR infrared and CZCS visible images may not always represent flow at the same depth, the measurements were practically identical with the data used.