Performance evaluation of combining ICESat-2 and GEDI laser altimetry missions for inland lake level retrievals

Abstract Monitoring lake water levels is important to fully understand the characteristics and mechanism of dynamic change, impact climate change human activities on lakes, etc. This paper first individually evaluated performance newly released Global Ecosystem Dynamics Investigation (GEDI) successor Ice, Cloud, Land Elevation Satellite mission (ICESat-2) for inland level retrieval over four typical lakes (Chaohu Lake, Hongze Gaoyou Lake Taihu Lake) using in situ gauge data, then two missions were combined derive long time-series levels. A comparison results with validated accuracy ICESat-2 R varying from 0.957 0.995, MAE 0.03 m-0.10 m RMSE 0.04 m-0.13 m; however, larger bias occurred GEDI spanning 0.560 0.952, 0.31 m-0.38 0.35 m-0.46 m. Before combined, correction was carried out. The correlation coefficients annual rate differences between data 0.964 0.06 m/yr, 0.852 0.05 0.888 0.899 0.02 m/yr Chaohu, Hongze, Taihu, respectively. Except individual months seasonal caused by estimations, general trend monthly, seasonal, dynamics captured consistent measurements hydrological stations. These encouraging demonstrate that combining has great potential frequent accurate monitoring could be a valuable resource study climatic change.