21 December 1994 Using cross-image spectra in a SAR ocean wave inversion scheme
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Cross-image spectra obtained by combining two sub-look SAR images are utilized in an inversion scheme for extrating the underlying ocean wave spectrum. The reasons for proposing the use of cross-image spectra instead of standard multilook spectra are twofold. First, the cross-image spectra are shown to significantly reduce the speckle noise level while preserving the spectral shape. Second, the cross-image spectra provide information about the wave propagation direction. A closed form expression of the ocean-to-SAR spectral transform and its inversion is formulated for the cross-image case. The SAR cross-image spectra are shown to yield a SNR typically 5 to 8 dB higher than the corresponding standard 3 look image spectra. The noise level is typically reduced with a factor of 2 compared to the 3 look spectra and a factor of 6 compared to the single sub-look spectra. The inherent information about the wave propagation direction are utilized in the inversion scheme to resolve the 180 degree ambiguity without using any external information. The method is demonstrated on airborne C- band SAR data.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Geir Engen, Geir Engen, Harald Johnsen, Harald Johnsen, Erik Korsbakken, Erik Korsbakken, } "Using cross-image spectra in a SAR ocean wave inversion scheme", Proc. SPIE 2319, Oceanic Remote Sensing and Sea Ice Monitoring, (21 December 1994); doi: 10.1117/12.197284; https://doi.org/10.1117/12.197284

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