
Accession Number : AD0669101
Title : WAVEFRONT OBSERVATIONS AT 35 GHZ ON A LINEOFSIGHT, RADIOWAVE PROPAGATION PATH.
Descriptive Note : Final rept. 1 Dec 6630 Nov 67,
Corporate Author : STANFORD UNIV CALIF STANFORD ELECTRONICS LABS
Personal Author(s) : Lee,R. W. ; Waterman,A. T. , Jr
Report Date : DEC 1967
Pagination or Media Count : 164
Abstract : Recent data taken with the 2800 lambda, 8element receiving array, at 35 GHz, over a 28km lineofright path are reported. The basic data consist of amplitude and relative phase, measured separately at each antenna element in a few milliseconds, with a 'scan' of all eight elements repeated each tenth of a second. From these data, the standard deviation of signal amplitude divided by the mean is computed, and sample from a 32hour run in July are plotted as a function of time of day. Similarly the standard deviation of phasedifference is so plotted. In like fashion the coherence of the wavefront is determined by the data and plotted against time of day, both for the July run and for an earlier April run. The same is done for the phase structurefunction. Both the measured phase structurefunction and the measured amplitude covariance are compared with theoretical models of atmospheric structure involving a spectral intensity proportional to some power (11 3, in the case of the Kolmogrov spectrum) of the turbulence wavenumber. The magnitude of the universal turbulence constant, required for consistency with the data is also obtained, and ranges slightly higher than the values observed by others. Finally, a systematic arrangement of significant data covering 67 twominute samples taken at hourly intervals, from the April and July runs, is included. For each of the 67 samples, four graphs are presented: (a) amplitude vs time for each element, (b) phasedifference vs time for each adjacent elementpair, (c) cross covariance of amplitude vs time lag, and (d) cross covariance of phase difference vs time lag. From these, basic information is made available in quantity. (Author)
Descriptors : (*MILLIMETER WAVES, *IONOSPHERIC PROPAGATION), RADIO TRANSMISSION, TROPOSPHERE, ANTENNA ARRAYS, RADIO WAVES, PHASE MEASUREMENT, INTENSITY, EXPERIMENTAL DATA, STATISTICAL FUNCTIONS, PHASED ARRAYS, ATMOSPHERE MODELS, ATMOSPHERIC MOTION, STATISTICAL ANALYSIS, GRAPHICS
Subject Categories : Radiofrequency Wave Propagation
Distribution Statement : APPROVED FOR PUBLIC RELEASE