Accession Number : AD0663412

Title :   WAVEFRONT STATISTICS IN 3.2-MM LINE-OF-SIGHT TRANSMISSION.

Descriptive Note : Rept. for Jun 66-Aug 67,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Heidbreder,G. R. ; Mitchell,R. L.

Report Date : OCT 1967

Pagination or Media Count : 32

Abstract : An experimental study of wavefront statistics in 3.2-mm wavelength CW transmission is described. The measurements were obtained on a 19-km horizontal path near sea level. Two receiving installations were used. One of these is an interferometer with variable element spacing along a horizontal baseline. Signal amplitudes at both elements and phase difference were recorded. Phase difference statistics and amplitude fluctuation correlations were obtained for station separations between 1 and 7 m under various meteorological conditions. The other receiving installation, which may be operated simultaneously with the interferometer, consists of a 4.57-m paraboloidal antenna and radiometer. The main beam of the antenna is 2.8-arc-min wide in free space and is measurably perturbed in a turbulent atmosphere. It may be scanned across a point source in a time short relative to the time constant of the atmospheric structure. The peak relative pointing error of 2.5 arc-sec is sufficiently small that sequences of rapid-scan 'instantaneous' antenna patterns may be superposed to obtain statistics of the pattern. Statistics of beam-wander and average antenna patterns are presented. Statistics obtained with the two receiving installations are compared with each other and with existing theoretical results. (Author)

Descriptors :   (*WAVE PROPAGATION, *MILLIMETER WAVES), ANTENNA RADIATION PATTERNS, ATMOSPHERIC MOTION, STATISTICAL FUNCTIONS, PROPAGATION, EXTREMELY HIGH FREQUENCY, RADIO INTERFEROMETERS, RADIOMETERS, PARABOLIC ANTENNAS

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE