Bathymetry of the littoral zone using hyperspectral images

Hyperspectral imagery (HSI) of the ocean-land interface, known as the littoral zone (LZ) can provide a valuable source of information for identification of underwater objects and materials, determination of water depth, and retrieval of water composition. The first step in the analysis is removal of atmospheric effects, resulting in surface reflectance spectra. The atmospheric removal is accomplished with a new version of the MODTRAN-based FLAASH correction code. When available, infrared wavelengths are used to retrieve water vapor and aerosol parameters for the correction and to remove foam and glitter components to yield water-leaving reflectance. A visible-only spectral unmixing technique for foam and glitter removal has also been developed. Bathymetry algorithms that use the 500-700 nm region were developed based on Monte Carlo-simulated “ground truth” spectra. The end-to-end data analysis process has been demonstrated with publicly available AVIRIS imagery.