Ocean Surface Drift by Wavelet Tracking Using ERS-2 and ENVISAT
Antony K. Liu(1) , Ming-kuang Hsu(2) , and Yunhe Zhao(3)
NASA/Goddard Space Flight Center,
Ocean Sciences Branch/Code 614.2,
Greenbelt, MD 20771,
(2) Northern Taiwan Institute of Science and Technolog, No. 2, Xue Yuan Rd., Taipei, 112, Taiwan
(3) Caelum Research Co, NASA/GSFC Code 614.2, Greenbelt, MD 20771 , United States
Due to high-resolution SAR data, the coverage of SAR sensor is always limited, especially for a repeat cycle. With more SAR sensors from various satellites, new data products such as ocean surface drift can be derived when two SAR’s track overlapped in a short time over coastal areas. This work may be the first time to be able to derive ocean surface current using the algorithm for feature tracking from two different SAR sensors on different satellites, such as ERS-2, and ENVISAT having 30 minutes acquisition offset. The two-dimensional Gaussian wavelet has been applied to satellite images to separate various scale processes including relative phase/location information for coastal watch applications and for ice edge, ice floe tracking, and sea-ice drift at NASA/GSFC. In SAR images, oceanic fronts, internal waves, oil spill and eddies are good features to track. The surface current has been derived from satellites observations overlapped in a short time over the coastal area by ERS-2 and ENVISAT using wavelet tracking technique. Some preliminary results of surface drift derived in the South China Sea and the east coast of Taiwan (Kuroshio boundary) will be presented and discussed.