Date of Award
Doctor of Philosophy
The Bay of Fundy, with its humid maritime climate, presents a hostile environment for the operation of microwave digital radio systems due to the frequent occurrence of multipath propagation. Therefore, a detailed knowledge of the ray path characteristics during multipath fading is of value to system and propagation path designers.;Two microwave propagation experiments were conducted on separate oversea paths across the Bay of Fundy in 1980 and 1981. A sweep frequency microwave diagnostic system operated with a frequency sweep from 9.5 to 10.5 GHz was used. The data collected provide information on various characteristics of the received ray(s). These include the amplitude, angle-of-arrival, and relative delay time of each ray. A digital radio test was also conducted during the 1981 experiment on an essentially identical propagation path.;The results from these experiments are presented to illustrate the propagation mechanisms associated with severe fading activities observed across the bay. In addition, statistics are presented on ray amplitudes, angles-of-arrival, delay times, and fade depth distributions. These results are related to the performance of the digital radio.;It is found that most of the severe fading activities result from the combined effects of atmospheric layers and the sea reflection. The properties of the sea reflected ray are discussed in detail as a function of sea surface roughness and atmospheric refractive properties. Particularly significant is the influence of atmospheric layers on the reflected ray. These layers have the effect of substantially increasing the relative delay time of the reflected ray to more than 10 nanoseconds. Auxiliary ray paths with such long delay times, which are rarely found in the literature, have significant impact on the operation of digital radio systems. In particular, the effectiveness of frequency diversity protection schemes are much reduced when these long delay ray paths are present.
Lam, Wang-leung Ignatius, "The Propagation Of Microwaves On Line-of-sight Oversea Paths" (1983). Digitized Theses. 1280.