The POLDER (POLarization and Directionality of the Earth's Reflectances) sensor was launched onboard the Japanese ADEOS satellite in August 1996. It measured the energy reflected by the Earth in the solar spectrum at 8 wavelengths. From this sensor, an Earth target could be seen up to 14 times along a single path providing a good characterization of the BRDF (Bidirectional Reflectance Distribution Function) from space. A set of one month of POLDER data over east Antarctica was analyzed. After cloud masking and atmospheric corrections, mean BRDFs were derived for different areas. In some parts of the ice sheet the BRDF is assymetric with a strong reflectance peak in the half space oriented towards the sun (backscatter). This peak is due to the anisotropic roughness of the surface (sastrugi) and its position depends on the sastrugi direction. ¿ 1999 American Geophysical Union