Remote sensing of diffuse attenuation coefficient (K490) using IRS-P4 Ocean Colour Monitor (OCM) sensor

Abstract

An algorithm relating the diffuse attenuation coefficient K(490) at 490 nm wavelengths to the ratio of normalized water-leaving radiance [L_wn(443)/L_wn(555)] has been developed through regression analysis of radiometric profiles obtained from three oceanographic cruises conducted in the north eastern Arabian Sea and off Orissa and Andhra coast in the Bay of Bengal. The regional K(490) algorithm has been applied on to the IRS-P4 Ocean Colour Monitor (OCM) satellite data and a limited validation of the algorithm has been performed for case I and case II waters off Gujarat coast in the Arabian Sea. The results of the satellite validation experiment conducted in the Arabian Sea for K(490) algorithm show that the algorithm captures very well the in situ K(490) values (RMS=0.011 m^-1). The algorithm has also been validated for an independent in situ data set collected during SK-186 data collection campaign in the Arabian Sea; a good correlation was obtained for this data (r² = 0.80, N=41).