Estimation of inherent optical properties using quasi-analytical algorithm along the coastal waters of southeast Arabian Sea

An integrated Satlantic hyperspectral profiler was used to collect radiometric quantities and fluorescence up to a depth of 50 m. Remote sensing reflectance (r(rs)) characteristics were analysed for the coastal waters of southeast Arabian Sea during 2013 to 2015. Inherent optical properties (IOPs) were derived from the radiometric measurements using quasi-analytical algorithm (QAA). Using hyperspectral remote sensing measurements, a better understanding of the optical properties such as backscattering and absorption for the coastal waters of southeast Arabian Sea was possible. Comparison between QAA-modelled and MODIS Aqua-derived absorptions at different wavelengths showed significant correlation (r = 0.753, 0.836, 0.714, 0.709, 0.714 and -0.347 at wavelengths 412, 443, 488, 531, 547 and 667 respectively) except for red band. The retrieval accuracy of MODIS Aqua Chl-a for the coastal waters of southeast Arabian Sea was considerably good with a correlation of 0.89 with profiler Chl-a concentration. QAA-modelled a(ph) at 443 nm and b(bp) at 555 nm showed a good correlation of 0.82 and 0.81 respectively with the in situ Chl-a concentration. The results of this study elucidate the optical complexity of southeast Arabian Sea coastal waters and support the use of QAA for better understanding of IOPs in the coastal case-2 waters.