Wavelet based bathymetry retrieval method for nearshore X-band radar images.

A wavelet based method for bathymetry retrieval from X-band radar images is proposed. Themethod combines traditional FFT techniques for retrieving peak frequency mapsby evaluation of spectral peaks in the time domain and localized 2D ContinuousWavelet Transform (CWT) for retrieving corresponding peak wavenumbers. Inorder to verify the proposed method 1D and 2D simulations of the wave shoalingover several bottom topographies based on a mild slope equation were performed.This model allows simulating wave shoaling and refraction. Wave breaking andreflection were neglected in our simulations. As a testing case, the shoaling of anincident monochromatic and JONSWAP spectrum-based wavefields were evaluated. Aradar image model including tilt and shadowing modulations together with specklenoise was applied to both 1D and 2D surface elevations. The method’s ability toreconstruct the original bathymetry is shown to be robust in intermediate to shallow waterdepths (kph < 1.2) for all the synthetic cases with varied probing geometry, bottomtopography and sea state conditions. After stochastic simulations checks, the methodwas also applied to the real data acquired by WaMoS system in Haifa Bay (Israel).Preliminary comparisons with known bathymetric surveys will be presented anddiscussed.