Accession Number : AD0478052


Title :   INVESTIGATION OF SPACE COMMUNICATIONS SYSTEMS USING LASERS.


Descriptive Note : Interim rept. Dec 63-May 64,


Corporate Author : MICHIGAN UNIV ANN ARBOR INST OF SCIENCE AND TECHNOLOGY


Personal Author(s) : Rollin,R A ,Jr ; Zwas,F


Report Date : Jan 1966


Pagination or Media Count : 180


Abstract : Space-to-space and earth-to-space communications systems with currently available laser sources have been studied and analyzed. Conclusions are drawn concerning the best continuous wave (CW) laser wavelength for both types of systems under various conditions, and areas of research are recommended. The general optical-communications range equation was derived using signal to noise considerations for the space-to-space and earth-to-space systems. The performance of seven laser systems employing state of the art components were compared. Two of these seven included optical maser power amplifiers. The 1.0628 micron SF6 + He gas laser source with a neodymium optical maser power amplifier performed best for deep-space laser communications from an earth station or from a space vehicle. The studies of geophysical and celestial phenomena affecting laser communications included the investigation of atmospheric transmittance and background interference from celestial bodies. The minimum elevation angle of the laser propagation path through the atmosphere was determined from data calculated in the transmission studies. It was also determined that laser communications through clouds and fog is impossible. The background interference work included studies of spectral irradiance of the sun, all nine planets, the moon, and the brighter stars as viewed from just outside the earth's atmosphere as well as the spectral radiance of the atmosphere from the earth and near space. The literature on components was searched. Satellite and ground-station spacings for continuous laser space communications were determined. (Author)


Descriptors :   *OPTICAL COMMUNICATIONS , *COMMUNICATION SATELLITES , SPACE COMMUNICATIONS , LASERS , ATMOSPHERIC REFRACTION , SPACE TO SPACE , SURFACE TO SPACE , POWER AMPLIFIERS , NEODYMIUM , SULFUR COMPOUNDS , FLUORIDES , GEOPHYSICS , BACKGROUND , PROPAGATION , INTERFERENCE , ATMOSPHERICS , CLOUDS , FOG , LIGHT TRANSMISSION , DETECTORS , REFLECTORS , SYNCHRONOUS SATELLITES


Subject Categories : Non-radio Communications


Distribution Statement : APPROVED FOR PUBLIC RELEASE