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

Attenuation Due to Roadside Trees: Mobile Case 3-25
entire frequency range (up to 20 GHz), although both are applicable between UHF and
S-Band.
Percentage of Distance Fade > Abscissa
100
9
8
7
6
5
4
3
2
10
9
8
7
6
5
1
4
3
2
0.893 GHz
Frequency Scaling Case
1.55 GHz
ERS Scaling
EERS Scaling
2.66 GHz
0 2 4 6 8 10 12 14 16 18 20
Fade Depth (dB)
Figure 3-23: Fade distributions at L-Band, S-Band and UHF measured by Bundrock and
Harvey [1988] (solid curves). The open circular and solid circular points represent the
ERS and the EERS frequency scaling estimates, respectively.
3.7 Comparison of EERS Model with Other Empirical Models
3.7.1 Modified Empirical Roadside Shadowing Model (MERS)
This model is an outgrowth of campaigns carried out by the European Space Agency
(ESA) [Jongejans et al., 1986] and is described by Sforza et al. [1993a; 1993b] and Butt
et al. [1995]. It is called the Modified Empirical Roadside Shadowing (MERS) and is
representative of mobile-satellite attenuation from deciduous trees corresponding to POS
values from 35% to 85%. The formulation has the same form as the ERS model (3-3)
and is given by
where
A ( P,
θ ) = −M
( θ ) ln( P)
+ N ( θ ) , (3-21)