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

3-12
Propagation Effects for Vehicular and Personal Mobile Satellite Systems
3.4 Validation of the Extended Empirical Roadside Shadowing Model
3.4.1 Central Maryland at L-Band
In Figure 3-10 is shown a comparison of the above EERS model at 1.5 GHz for
distributions derived from measurements in Central Maryland using a helicopter as the
transmitter platform for an elevation angle of 45° [Goldhirsh and Vogel, 1989]. Shown
are eight cumulative distributions corresponding to eight runs with different scenarios
pertaining to three roads in central Maryland. The first legend item refers to the EERS
model curve (solid black line) which is shown to approximate the median of the
distributions whose fade values at any given probability are within ±5 dB of the measured
distributions. The next item in the legend refers to Route 295 driving south (295 S), right
lane driving (RL), with the helicopter on the right (HR). The other items in the legend
have analogous definitions. Sets of other distributions were derived for elevation angles
of 20°, 45°, and 60° with similar results associated with the EERS model [Goldhirsh and
Vogel, 1995b].
Percentage of Distance Fade > Abscissa
100
9
8
7
6
5
4
3
2
10
9
8
7
6
5
1
4
3
2
Legend
EXTENDED ERS
295 S, RL, HR
295 N, RL, HR
295 S, LL, HR
295 N, LL, HR
108 SW, HL
108 NE, HL
32 N, HL
32 S, HL
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Fade (dB)
Figure 3-10: Comparison of EERS (solid black curve) model distribution with
cumulative distributions for eight runs in central Maryland at 1.5 GHz and elevation
angle of 45°.