Accession Number : AD0285247

Title :   EVALUATION OF AN EXPERIMENTAL LASER-RANGING SYSTEM

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : TODD,ALTON B.

Report Date : AUG 1962

Pagination or Media Count : 1

Abstract : A simple Laser-ranging system was built and experimentally evaluated regarding signal-to-noiseratio versus range attainable. The transmitter consists of a technical research group model V2909 commercial Laser equipment and a collimator to reduce the beamwidth. The receiver consists of a 36-in. parabolic mirror focused on an RCA 7265 photomultiplier. The dominant sources of noise in the system are background sunlight and backscattering of Laser energy. Measurement of interference owing to sunlight for targets of high reflectance shows a slightly decreasing value with range which agrees with theory presented, but a general level 8 db higher than predicted. Measurements of backscattering received show the characteristic rapid buildup and leveling off with range predicted by the theory and a very comparable magnitude. Return signal strength vs range was determined by extrapolation of measurements on one target. This was compared with the sum of the two dominant noise sources to obtain signal-to-noise-ratio. Measured signal-to-noise-ratio thus obtained compares favorably with the predicted value except for a greater day-night difference resulting from the greater than predicted sunlight interference. (Author)

Descriptors :   DESIGN, INTERFERENCE, LASERS, LIGHT, OPTICAL EQUIPMENT, PHOTOMULTIPLIER TUBES, RANGE FINDING, REFLECTION, SCATTERING, SIGNAL-TO-NOISE RATIC, SOLAR SPECTRUM

Distribution Statement : APPROVED FOR PUBLIC RELEASE