A suite of instruments mounted in the payload bay of the Endeavour space shuttle and operated by the crew on two topographical Earth-mapping missions, SRL-1 and SRL-2, launched as STS-59 on 9 April 1994 and STS-68 on 30 September 1994. SRL contained the US spaceborne imaging radar SIR-C, and the German–Italian X-band synthetic aperture radar. The 11-day missions each imaged over 400 target sites covering the equivalent of 20% of the Earth's surface. The topographical elevation images were derived by measuring the reflection of radar pulses (emitted from the shuttle) back from the Earth's surface.
Subjects: Astronomy and Astrophysics.