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

Chapter 12
Summary of Recommendations
The major recommendations of the individual chapters are succinctly summarized here
along with caveats and suggestions for future work. Elaboration of the formulations
including pertinent references may be found in the designated chapters.
12.1 Introduction (Chapter 1)
An overview of the contents of the individual chapters in this text is given. Also included
is a description of how to access the contents of this document from the World Wide Web
at http://www.utexas.edu/research/mopro/index.html. The authors encourage the readers
to send their suggestions and comments to them by accessing this address.
12.2 Average Foliage Attenuation Due to Trees: Static Case (Chapter 2)
Attenuation levels and formulations for stationary earth-satellite paths passing through
canopies of trees are described. Canopy attenuation at frequencies ranging from 870
MHz to 20 GHz is considered.
12.2.1 Average and Median Foliage Attenuation Due to Tree Canopies
The average measured attenuations due to tree canopies for multiple tree-types are as
follows: (a) 11 dB at 870 MHz with a 3 dB RMS, (b) 11 dB at 1.6 GHz with a 5 dB
RMS. At 20 GHz, the median canopy attenuation is 23 dB. The RMS deviations are
based on multiple measurements for different tree types, densities of foliage, and variable
path lengths through the foliage.
12.2.2 Frequency Scaling
The following frequency scaling formulation has been validated at frequencies of
870 MHz, 1.5 GHz, 3 GHz and 20 GHz