Page 103 - Fundamentals of Radar Signal Processing

(2.37)

Instead of a single real number, the target backscattering characteristics are now
described by four complex numbers. If the radar transmitted and received, say,

only the vertical component, then the RCS σ would be related to S by

(2.38)

Radars can be designed to measure the full complex PSM. Other designs
measure the magnitudes but not the phases of the elements of the PSM, or the
magnitudes of two of the PSM elements. These polarimetric measurements can
be used for a variety of target analysis purposes. However, a discussion of

polarimetric techniques is beyond the scope of this book. Henceforth, it will be
assumed that only a single fixed polarization is transmitted and a single fixed
polarization received, and consequently that RCS is described by a scalar,
rather than matrix, function. The reader is referred to the works by Holm (1987)
and Mott (1986) for discussions of polarimetric radars and polarimetric signal
processing.

2
Typical values of RCS for targets of interest range from 0.01 m (–20 dB
with respect to 1 m , or –20 dBsm) to hundreds of square meters (≥ +20 dBsm).
2
Both larger and smaller values are also observed. Table 2.1 lists representative
RCS values for various types of targets.