Analysis of EO-1 Hyperion over Agatti and Boat Islands, India

Abstract

Amongst the available satellite remote sensing options to distinguish between various shallow water habitat classes, such as healthy corals, algal cover, sea-grass cover, degraded corals, algal ridges, reef flat, knolls, lagoon, debris and sandy areas, hyperspectral remote sensing is one of the best options by virtue of its spectral capabilities, while high spatial resolution still being a necessary and sufficient condition to spatially resolve fine morphological features. Even with high spatial resolutions (5-30 m), the accuracy through unsupervised classification of different eco-morphological classes is an issue without appropriate in situ verification to resolve artifacts. In addition, the discrimination capability of habitat classes using multi/hyperspectral satellite data is dependent on the efficacy of the correction scheme for the atmospheric effects and the intervening water-column. In the present study, a seamless ocean-atmospheric correction called Coupled Ocean Atmospheric Radiative Transfer (COART) was applied to Earth Observation (EO-1) Hyperion data acquired over the coral reefs of Agatti Island in the Lakshadweep Islands and Boat Island in the Andaman Islands, India. The results from the study indicate that correction for the intervening water column helps in identifying submerged features in the reef slope and reef flat. The study concludes that the Hyperion data have sufficient discrimination capabilities for classification of broad habitat classes and can further be improved by using coupled radiative transfer models.