Radiance-ratio algorithm wavelengths for remote oceanic chlorophyll determination

Two-band radiance-ratio in-water algorithms in the visible spectrum have been evaluated for remote oceanic chlorophyll determination. Airborne active-passive (laser-solar) data from coastal, shelf-slope, and bluewater regions were used to generate 2-D chlorophyll-fluorescence and radiance-ratio statistical correlation matrices containing all possible two-band ratio combinations from the thirty-two available contiguous 11.25-nm passive bands. The principal finding was that closely spaced radiance-ratio bands yield chlorophyll estimates which are highly correlated with laser-induced chlorophyll fluorescence within several distinct regions of the ocean color spectrum. Band combinations in the yellow (~565/575-nm), orange-red (~675/685-nm), and red (~695/705-nm) spectral regions showed considerable promise for satisfactory chlorophyll pigment estimation in near-coastal Case II waters. Based on very limited data, pigment recovery in Case I waters was best accomplished using blue-green radiance ratios in the ~490/500-nm region.