Mapping lake topography using high-resolution ALOS PRISM data

Lake topography is necessary to estimate lake water storage valuable for studying hydrological processes. Lake surveying is generally tedious and time-consuming, and the spatial resolution of existing digital elevation models (DEMs) is generally limited. The Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard ALOS has a spatial resolution of 2.5-m. It offers a way to mapping lake-basin with a high spatial resolution. We used PRISM L1B2 data to map the topography of Poyang Lake, the China´s largest freshwater lake, located in a subtropical area of China. We used three-dimensional geographic control points and satellite ephemeris parameters to generate rational polynomial coefficient (RPC) and subsequently built stereo images to extract lake-basin terrain. In the tested case, our results showed that the extracted lake-basin achieved a satisfied accuracy. The high spatial resolution data also generated the detailed terrain features. It should be useful for studying spatial variation of large-scale lakes.