Author/Authors :
Mobley، Curtis D. نويسنده , , Sundman، Lydia K. نويسنده , , Davis، Curtiss O. نويسنده , , Bowles، Jeffrey H. نويسنده , , Downes، Trijntje Valerie نويسنده , , Leathers، Robert A. نويسنده , , Montes، Marcos J. نويسنده , , Bissett، William Paul نويسنده , , Kohler، David D. R. نويسنده , , Reid، Ruth Pamela نويسنده , , Louchard، Eric M. نويسنده , , Gleason، Arthur نويسنده ,
Abstract :
A spectrum-matching and look-up-table (LUT) methodology has been developed and evaluated to extract environmental information from remotely sensed hyperspectral imagery. The LUT methodology works as follows. First, a database of remote-sensing reflectance (R_rs) spectra corresponding to various water depths, bottom reflectance spectra, and water-column inherent optical properties (IOPs) is constructed using a special version of the HydroLight radiative transfer numerical model. Second, the measured Rrs spectrum for a particular image pixel is compared with each spectrum in the database, and the closest match to the image spectrum is found using a leastsquares minimization. The environmental conditions in nature are then assumed to be the same as the input conditions that generated the closest matching HydroLight-generated database spectrum. The LUT methodology has been evaluated by application to an Ocean Portable Hyperspectral Imaging Low-Light Spectrometer image acquired near Lee Stocking Island, Bahamas, on 17 May 2000. The LUT-retrieved bottom depths were on average within 5% and 0.5 m of independently obtained acoustic depths. The LUT-retrieved bottom classification was in qualitative agreement with diver and video spot classification of bottom types, and the LUT-retrieved IOPs were consistent with IOPs measured at nearby times and locations.
