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

Earth-Satellite Propagation Effects Inside Buildings 8-13
co-polarized measurements, the experimental procedures were repeated with crosspolarized
receiving antennas in order to establish the efficacy of frequency reuse
employing multiple polarizations.
Measurements were made into six different buildings during the Fall of 1994. The
names of these buildings, pertinent construction details, and the path elevation angles are
given in Table 8-7. EERL, The Commons, and the Farmhouse were previously referred
to by Vogel and Torrence [1993] (Section 8.2) as Sites 1, 3, and 5, respectively in Table
8-2.
The van with processing instrumentation and mounted tower was placed outside of
each of the buildings, and transmissions from the radiating antenna simulated those
emanating from a satellite. Each experiment included a calibration procedure during
which the co-polarized power level was measured outside the building. This co-polarized
power level was used as a relative reference (clear line-of-sight) of the power
measurement interior to the building.
Table 8-7: Building characteristics and measurement parameters.
Building
Name
Year of
Construction
Construction
Type
Roof
Type
Avg. El.(°)
Commons 1987 concrete tilt wall tar 16 16
EERL Office 1944 block brick tar 30 8.8
Farmhouse 1880 wood frame wood shingle 57 19.2
House 1958 wood frame composition 40 12
Motel 1980 brick composition 26 8
Store 1967 steel frame tar 37 16
8.3.2 Stability of Measurement
Distance
Meas. (m)
An example of a 50 second time series of power is given in Figure 8-7 for L- and
S-Bands for the Commons for both co-polarized and cross-polarized levels at fixed
antenna positions. The standard deviation for the case shown is less than 0.2 dB at
L-Band and S-Bands. Similar stability measurements were executed at the five other
sites and the overall average of the standard deviations was less than 0.5 dB at both
frequencies. This variability is a measure of the uncertainty in the measurements and
reflects system stability, possible transmitter motion, people motion, and ambient
interference.