Page 510 - Fundamentals of Radar Signal Processing

FIGURE 6.22 Illustration of target masking. See text for details.

Precise analysis of the effect of a target in the reference cells is
conceptually simple but somewhat complicated in practice. However, a
relatively simple approximation that illustrates the effect of an interfering target
can be derived. Consider a single interfering target with power γ that
i
contaminates only one of the N CFAR reference cells. The mean SNR of this
interferer is . The expected value of the new threshold will be

(6.147)

Thus, is again a multiple of the interference power as in Eq. (6.129)

but with a multiplier α′ given by

(6.148)

The elevated threshold will decrease both the P and P . Using Eq. (6.148) and
FA
D
Eq. (6.135) in Eq. (6.137) gives an expression for the new value of in terms
of the original design value of