Assessment of ICESat performance at the salar de Uyuni, Bolivia

6 [1] The primary goal of the Ice, Cloud and land Elevation 7 Satellite (ICESat) mission is ice sheet elevation change 8 detection. Confirmation that ICESat is achieving its stated 9 scientific requirement of detecting spatially-averaged 10 changes as small as 1.5 cm/year requires continual 11 assessment of ICESat-derived elevations throughout the 12 mission. We use a GPS-derived digital elevation model 13 (DEM) of the Salar de Uyuni, Bolivia for this purpose. Using 14 all twelve ICESat passes over the salar survey area acquired 15 to date, we show that the accuracy of ICESat-derived 16 elevations is impacted by environmental effects (e.g., 17 forward scattering and surface reflectance) and instrument 18 effects (e.g., pointing biases, detector saturation, and 19 variations in transmitted laser energy). We estimate that 20 under optimal conditions at the Salar de Uyuni, ICESat21 derived elevations have an absolute accuracy of <2 cm 22 and precision of <3 cm. Citation: Fricker, H. A., A. Borsa, 23 B. Minster, C. Carabajal, K. Quinn, and B. Bills (2005), 24 Assessment of ICESat performance at the Salar de Uyuni, 25 Bolivia, Geophys. Res. Lett., 32, L21S06, doi:10.1029/ 26 2005GL023423.