DESIGN STUDY OF ADVANCED GEODETIC LASER SYSTEM,

The Geodetic Laser System described herein is to generate two intense beams of radiant energy so that a portion reflected from an assembly of retrodirective reflectors on a satellite can produce a detectable and identifiable point image on a photographic plate and an unambiguous photoelectric voltage pulse. The photographic image, taken against a calibrated stellar background, will be used to measure the angular position of the satellite, and the photoelectric signal to measure its slant range. These measurements will be made almost simultaneously and together establish the vector displacement between the ground-based laser system and the satellite at the time of observation. The distance to the satellite is generally more than 1000 km. The desired accuracies of the angular and range measurements are to less than 2 arc-seconds and to less than 10 meters respectively. Multiple observations will be made in each orbital pass to enhance identification of the photographic image and collect more data. The requirements and specifications for all major system components are established so that a reasonable compromise between desired performance and costs will be achieved. Design is carried out in detail only to the point of assurance that technological state-of-the-art exists which is consistent with the system requirements and the specifications. Author