OCEAN WAVE MEASUREMENTS IN HIGH AND COMPLEX SEA STATE BY SAR WAVE MODE DATA AND NUMERICAL WAVE MODEL

摘要

The Synthetic Aperture Radar (SAR)rnonboard the European Satellite ERS-2 is operated inrnwave mode over the global oceans, whenever nornimage mode data acquisition is requested. In thernscope of the Wave Atlas Project, ESA provided arntwo-year wave mode dataset of ERS-2 SAR rawrndata mainly collected during 1999 and 2000, whichrnwas reprocessed to single-look-complex (SLC)rnimagettes at DLR using the BSAR processor. Thernprocessed dataset contains daily between 1300 andrn1500 images of 5 km (azimuth direction) by 10 kmrn(range direction) size acquired over the globalrnocean.rnIn the present paper new algorithms to derive searnstate developed at the German Aerospace Centerrn(DLR) are briefly introduced and used to determinernSAR derived individual and spectral sea staternparameters.rnAs an example, a severe North Pacific storm, whichrnproduced significant wave height (SWH) above 10rnm along the northern great circle shipping route, isrnpresented. The sea state generated is analyzed inrndetail using the comparison of SWH derived fromrnERS SAR, Altimeter and the ocean wave modelrnWAM. The results are intercompared and validated.rnFurther an example of a cross sea is analyzed. Arncross sea case occurred in the South East Pacific andrnwas captured clearly by consecutive ERS-2 SARrnwave mode images acquired on August 10, 2000 atrn17:31 UTC. The WAM model spectra, SAR crossrnspectra and nonlinear SAR retrieved (PARSA)rnspectra together with derived integral parameters ofrnthe spectra as retrieved from SAR images are used tornanalyze the generation and development of the crossrnsea.