Popis: |
A large number of collocated in situ observations and ERS SLC Image Mode data are used to simulate the performance the Envisat ASAR Wave Mode Level 1 b product (the cross spectra product). Selecting the optimal combination of processing parameters the Level 1 b product will perform as follows in terms of detecting long wave (swell) systems: swell system detected, and propagation ambiguity resolved in 95% of the cases; swell system detected, but propagation ambiguity not resolved in 5% of the cases. The RMS error of the measured spectral parameters versus the simulated are as follows: spectral peak wavelength RMS=50 m; spectral peak propagation direction RMS=40/spl deg/; spectral peak phase value RMS=0.10 rad. The mean peak wavelength is 250 m, the mean peak phase value is 0.17 rad, and the mean azimuth cut-off length is 267 m. |