Spectral Information Analysis for the Semiautomatic Derivation of Shallow Lake Bathymetry Using High-resolution Multispectral Imagery: A Case Study of Antarctic Coastal Oasis

Bathymetry is a technique of measuring depths to determine the topography of water bodies. The derivation of bathymetry from satellite imagery is one of the basic researches in remote sensing of the aquatic environment, which has several practical implications to the coastal environment and it's monitoring. The spectral band information provided by the multispectral (eight bands) Worldview-2 (WV-2) satellite improves the quality of coastal environmental products including bathymetry. This study provides a method for mapping of shallow lake bathymetry (depth) in Larsemann hills, eastern Antarctica, using digital WV-2 imagery. Out of various bathymetry determination models available for multispectral images, two most popular models- linear band and linear ratio model were used to estimate water depth of the shallow water bodies. These models were executed using various band combinations to study their specific role in bathymetry derivation. The derived depths were validated against the in-situ measurements and root mean square errors (RMSE) were computed. We quantify the error between in-situ measured and satellite-estimated lake depth values for lakes selected in this study. Our results indicate the high correlation (0.7∼0.9) between estimated and in situ depth measurements, with RMSE ranging from 0.2 to 1 m. This study suggests that the coastal band in the WV-2 imagery could retrieve accurate bathymetry information compared to other bands.