Handbook of Propagation Effects for Vehicular and ... - Courses

Chapter 7
Investigations from Different Countries
7.1 Background
The results described here provide a compendium of measured cumulative fade
distributions for LMSS geometries pertaining to significant experiments in various
countries. We emphasize distributions associated with rural and suburban regions as
opposed to measurements in urban environments. In comparing the results of the
different investigations, the reader should be cognizant of the fact that the various
experiments were conducted at a variety of elevation angles and bearings to the source.
The diverse geographic regions (e.g., wooded, forest, rural, mountainous, highways) also
have associated with them dissimilar conditions of foliage density along the propagation
path, and variable distances between vehicle and foliage line. Many of the distributions
presented here have been extracted from their publication plots and have been re-plotted
consistent with the scales considered in this text; namely; the fade (in dB) along the
abscissa and the percentage of distance exceeded (or percentage probability) along the
ordinate. In the re-plotting of curves, accuracy to within ± 0.5 dB has been maintained.
Table 7-1 summarizes the pertinent mobile satellite measurement investigations. Also
given in these tables are the nominal fade values at the 1% and 10% levels (to the nearest
0.5 dB), the referenced figure numbers in this chapter, the type of environment, and the
corresponding publication reference. It is apparent from the wide variance of fades in
these tables (at any given frequency), that elevation angle and environment play
important roles in the determination of LMSS attenuation. Table 7-2 (at the end of this
chapter) summarizes the results of Table 7-1 by combining environments for given
elevation angle and frequency intervals.
7.2 Measurements in Australia
Bundrock and Harvey [1989] reported on cumulative fade distributions obtained on
typical double-lane roads in Melbourne, Australia. Messmate (stringy-bark) Eucalyptus
trees approximately 15 m high lined the road and measurements were made over sections