Bottom influence on the reflectance of the sea

Solar irradiance reflectance spectra of seawater with a variable content of particulate and dissolved materials as well as a variable bottom depth and composition were calculated. A two-flow radiative transfer model was employed, where the spectral signatures, characteristic for diverse seawater and bottom types, were introduced as input parameters. Optical signals in the spectral bands of LANDSAT MSS and TM, SPOT HRV and TIROS-N AVHRR scanners were computed in order to establish algorithms for remote determination of the bottom depth and composition. Several algorithms were proposed and their applicability discussed. The algorithms appear to be applicable down to depths of 3-20 m, depending on the water column and bottom composition.