Chromaticity analysis of the Chilika lagoon for total suspended sediment estimation using RESOURCESAT-1 AWiFS data - A case study

The chromaticity analysis of the Chilika lagoon has been attempted using RESOURCESAT-1 AWiFS data (10-bit radiometric resolution) of 26 November 2003. The total suspended sediment (TSS) concentration of surface waters of the lagoon was analyzed using a satellite-based chromaticity technique. The chromaticity coordinates of the entire lagoon were computed. As the lagoon is rich in biodiversity, five chromatically different regions have been identified based on different reflectance signatures. The technique is validated using the ground-truth data of high turbid water, low turbid water, aquatic vegetation, short grasses, and shallow turbid water. Different features clearly separate out on a chromaticity plot. The x-coordinate of the chromaticity shows better correlation with TSS in comparison to y-coordinate of chromaticity. The proposed approach is valuable for a quick estimate of TSS, an important geophysical parameter, which accounts for the water quality of the lagoon. The technique can be applied to compute the moderate TSS (e.g. up to 42 g m− 3) in a lagoon or any inland water body given the chromaticity image.