Satellite remote sensing provides unique opportunities for observing ice- covered terrain. Passive microwave data give information on snow cover on land, sea ice extent and type, and zones of summer melting on the polar ice sheets, and they have the potential of estimating snow accumulation rates on these ice sheets. All-weather, high-resolution imagery of sea ice is obtained by using synthetic aperture radars, and ice movements vectors can be deduced by comparing sequential images of the same region. Radar altimetry data provide highly detailed information on ice sheet topography and have the potential of deducing thickening/thinning rates from repeat surveys. The coastline of Antarctica can be mapped accurately using altimetry data, and the size and spatial distribution of icebergs can be monitored. Altimetery data also distinguish open ocean from pack ice, and they give an indication of sea ice characteristics.