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Communications Range Predictions for Mobile Radio Systems

NCJ Number
117431
Date Published
1989
Length
18 pages
Annotation
This document focuses on the mobile antenna, its location on a patrol car, and how the radio frequency and antenna location affect azimuthal coverage and nominal range.
Abstract
This report is an extension of an earlier work in which azimuthal power gain radiation patterns of mobile antennas mounted in six different locations on a test vehicle were measured with and without typical lights and siren mounted on the roof. The patterns were measured in each of four public safety frequency bands and, in addition, the patterns of several covert antennas and a slot antenna were measured. This work computes the cumulative distribution of power gain for each of the measured radiation patterns. The usefulness of this information is extended by computing estimates of propagation range for each case - based on nominal assumptions of certain system and environmental parameters. These new results also provide a realistic way of comparing antenna performance, since the orientation of the vehicle and the direction to a base station are unknown. 8 figures, 2 references, appendix.