Mapping mean lake surface from satellite altimetry and GPS kinematic surveys

Lake water height is a key variable in cycle and climate change studies, which achievable using satellite altimetry constellation. A method based on data processing of from several satellites has been developed to interpolate mean lake surface (MLS) over set 22 big lakes distributed the Earth. It applied nadir radar altimeters Low Resolution Mode (LRM: Jason-3, Saral/AltiKa, CryoSat-2) Synthetic Aperture Radar (SAR) mode (Sentinel-3A), SAR interferometric (SARin) (CryoSat-2), laser (ICESat). Validation performed kinematic GPS profiles 18 field campaigns Issykkul, by comparison altimetry’s at crossover points for other ICESat-2 mission. The precision reached ranges 3 7 cm RMS (Root Mean Square) depending lakes. Currently, level inferred provided with respect an ellipsoid. Ellipsoidal heights are converted into orthométric geoid models interpolated along tracks. These global were geodetic missions coupled absolute regional anomaly gravity sets spread However, spatial resolution current does not allow capturing short wavelength undulations that may reach decimeters mountaineering regions or rift (Baikal, Malawi, Tanganika). We this work anomalies three recent models, EGM2008, XGM2016 EIGEN-6C4d, compare them Surface calculated altimetry. Assuming MLS mimics local geoid, our study shows large (in East Africa, Andean mountain Central Asia), poorly sampled areas can be derived used present very similar geographical patterns when compared MLS. largely depends location about cm, average serve as validation dataset any future model. will also useful mission SWOT (Surface Water Ocean Topography) measure map high horizontal 250 m.