Mountain Obstacle Diffraction Measurements at 751 Mc/s and 9.2 Gc/s

Abstract

This paper contains results of a measurement program on 751 Mc/s and 9.2 Gc/s using a long mountain-obstacle diffraction path in Colorado. Data are analyzed and evaluated in terms of long· term and short-term variability, correlation coefficients between carrier envelopes received on spaced antennas, and comparison of a priori predicted and measured cumulative distributions of hourly transmission loss medians. Results show beuer agreement between predictions and measurements on 751 Mc/s than on 9.2 Gc/s. Short-term (within-the-hour) variations in signal level on 751 Mc/s can be characterized as prolonged space-wave· fadeouts, whereas such variations on 9.2 Gc/s verv frequently show characteristics of a Rayleigh-distributed signal.

U.S.A. National Committee Report, Fifteenth URSI General Assembly, Munich, September 1966: Commission 2, Radio Propagation in Nonionized Media; Progress in Radio Propagation in Nonionized Media

“…The occasional presence of strong refractive anomalies over land is suggested by pronounced long-term fading (space-wave fadeouts) on both line-of-sight and obstacle diffraction paths [Barsis, Barghausen, and Kirby, 1963;Barsis and Hause, 1966].…”

On Height‐Gain Studies Over a Long Mountain‐Obstacle Diffraction Path

“…Fairweather, Alaska [Dickson et al 1953] and was pointed out later by Crysdale [ 1955].Recalculation of the transmission-loss dependenco on height for both the east and the west receiving antennas at 751 MHz showed that only one single lobe exists within the range for which measured heightgain data are available. New comparisons of calculated and measured data are shown inFigure 1, separately for the 'east' and 'west' receiving antennas (as defined byBarsis and Hause [ 1966]). The calculated transmission-loss curves are based on the path geometry described in the same paper (seeFigure 14…”