SRTM

In February 2000, Space Shuttle Endeavour started on an 11-day SRTM (Shuttle Radar Topography Mission) remote sensing mission. It carried in its loading bay SIR-C (NASA) and X-SAR (DLR with ASI participation), two active radar sensors for deriving global elevation models using the single pass technique. For this purpose the antenna in the loading bay was used as a transmitter and receiver, with another receiving antenna at the end of a 60-meter mast that extended from the payload bay. The orbit of the space shuttle was designed so that the ground track of the U.S. SIR-C instrument could just manage to cover the land mass between 54° S and 60° N. Because of its higher resolution, the X-SAR instrument had a narrower ground track, leading to reduced coverage..