TABLE OF CONTENTS Maurice W. Long
Private Consultant Atlanta, Georgia
This chapter includes discussions on the average radar cross section (RCS) of targets and clutter, their fluctuation properties, and the detection of targets in the presence of noise and clutter. It specifically addresses, when possible, the causes for variation in the RCS of targets and clutter, and the statistical principles used in radar echo analysis. Example RCS values applicable to AEW are given for targets and clutter. Statistical target and clutter models that have proved useful for radar system analyses are also discussed. Finally, basic background material and sample problems are included on the detection of targets in the presence of noise and clutter.
Radar cross section (RCS) is a frequently used term, because a target's echo power is directly proportional to it (Chapter 4). RCS, which is often denoted by the symbol ?, is expressed as
| (5.1) |  |
where
| p r | = power density at a distance R from a target of RCS ? |
| p t | = power density incident on the target. |
The dimensional units of ? are area. For example, when power density and R are expressed in watts per square meter and meters, respectively, ? is expressed in square meters (m 2).
It is sometimes useful to know that ? equals the projected area of an object that scatters equally in all directions (isotropically). For example, the power incident on a target P t
