An Approach for Extracting Coral Reef Environs by Interpreting Multi-Dimensional SAR and Multispectral Data

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This study explore the SAR coupled with optical data for the delineation of coral reef area in and around the Boat Island of Andaman. The study found that wave interactions with the microwave signal make the spectacular pattern which leads to the delineation of coral area from SAR data. IRS RISAT-1 has the capability to acquire image in different polarization and incident angle, which is explored in this study to segregate coral from the open ocean. K-means unsupervised classification was performed on SAR image and the result shows the high incident angle (43.39\( {}^{\circ} \)) HV polarized image was suitable for delineating the reef edge because of the linear stretch of wave breakage. The low incident angle (27.04\( {}^{\circ} \)) HH polarized image was found to suitable for identifying reef flats in the coastal zone by comparing the wave action in open sea. The protection of Coral reefs requires frequent monitoring. However accessing such area in Andaman Islands is very difficult task due to accessibility, security and climatic concerns. Hence the study proposed to use radar coupled with multispectral image for coral reef mapping in such area. However data selection should be based on study area environments, wave direction and wave height.