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

Attenuation Due to Roadside Trees: Mobile Case 3-13
3.4.2 Australian Fade Distributions at L-Band
In Figure 3-11 is shown a comparison of the EERS model with measurements made in
Australia by the authors at 1.55 GHz [Vogel et al., 1992]. The Australian cumulative
distribution reflects measurements made over a distance of 403 km comprising 15
individual runs in the Sydney region using the Japanese ETS-V geostationary satellite.
The elevation angle to the satellite was 51°. Two major vegetation zones were traversed;
forests along the coastal roads and woodlands further inland. Forests ranged from dry
sclerophyll, in which the crowns of contiguous trees did not touch each other to tropical
rain-forests, in which the leafy crowns of the trees intermingled. The dominating tree
genus in the forests was Eucalyptus. Other than tree types, general similarities existed
between the roads traveled in Australia and those in central Maryland (e.g., tree heights,
POS, setbacks). Shown also is the EERS model at 51°. We note that the maximum
difference between the two distributions is less than 2 dB, which occurs at 14%. The
differences reduce monotonically above and below this percentage.
Percentage of Distance Fade > Abscissa
100
9
8
7
6
5
4
3
2
10
9
8
7
6
5
1
4
3
2
Distribution
Australia (ETS-V)
EERS Model
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Fade Depth (dB)
Figure 3-11: Comparison of Australian fade distribution with EERS model at elevation
angle of 51° at a frequency of 1.55 GHz.