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

Investigations from Different Countries 7-13
7.6 France and Germany: European K-Band Campaign
The European Space Agency commissioned a mobile measurement campaign at
18.7 GHz in various types of environments in the Netherlands, France, Germany, and
Austria employing the Italsat F1 satellite as a radiating source platform [Murr et al.,
1995; Joanneum Research, 1995; Paraboni and Giannone, 1991]. The elevation angles
were 30° to 35° and the roads selected were such that the azimuth directions of driving
relative to the satellite were 0°, 45°, and 90°. A tracking receiver antenna (2.4°
beamwidth) mounted on the roof of a van was utilized in the measurement campaign.
Figure 7-14 shows three distributions at azimuths of 0°, 45°, and 90° where the
distributions at 45° and 90° coincide. It is interesting to note that although 0° azimuth
represents the condition that the satellite was either in front of or in back of the moving
vehicle, substantial fades may nevertheless result due to the possibility of overhanging
foliage or bends in the road. Figure 7-15 shows distributions for three tree-shadowed
cases corresponding to driving azimuths of 0°, 45°, and 90° in Germany. The
corresponding measurements were executed in dense needle-tree forests. It is interesting
to note that the 45° degree satellite orientation gave larger fades than the 90° case. This
may be explained by the fact that because of gaps between the trees greater visibility to
the satellite exists at 90° relative to the 45° case. At this latter azimuth, the canopies
obstructed gaps between the trees. This was not always the case as is exemplified by the
distributions shown in Figure 7-14 obtained for France in a deciduous tree forest. For
this case, the 45° and 90° distributions effectively coincide.
Percentage of Time Fade > Abscissa
100
9
8
7
6
5
4
3
2
10
9
8
7
6
5
1
4
3
2
Orientation
45° and 90°
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Fade Depth (dB)
Figure 7-14: Cumulative fade distributions from measurements made in France at
18.7 GHz in a tree-shadowed environment at elevation 30° … 35°. The indicated angles
are the driving direction azimuths relative to the satellite [Murr et al., 1995].
0°