ERS-1 Antarctic map, Lake Vostok marked

Relief map of the Antarctic ice sheet derived from ERS-1 data. Lake Vostok shows up as an unusually smooth area of ice (highlighted). The main surface features such as ice divides, domes, ice stream outflow and drainage basins are well defined. Over 20 million height estimates were used to generate a 10 km Digital Elevation Model of the ice sheet which is accurate to better than 1 m for slopes less than 0.5 degrees.

South of the latitudinal limit of the satellite (81.5degrees) a terrestrially derived dataset was used with a substantial reduction in both the accuracy and short wavelength detail (as can be seen in the diagram).