Space reflectors for radar and astronomy

A new concept to utilize large flat optical reflecting surfaces in space to increase by several orders of magnitude the sensitivity and resolution of earth laser radar and astronomy measurements is described. The physical principles on which simple structures can maintain the optical reflectance gratings in space are derived, and the data processing requirements of the measurements are discussed. Space and ground system designs are given for a high resolution earth resources laser radar sensor, a synchronous earth and planetary science laser radar system, and an astronomy observation system including a variable very long compound grating interferometer system.