Page 138 - Fundamentals of Radar Signal Processing

FIGURE 2.23 Decorrelation time of windblown tree clutter versus frequency
and wind speed. [Data from Currie (2010)].

Another model frequently used to model generic power spectra is the
Gaussian given by

(2.68)

The Gaussian model is very commonly used in weather radar, and is the basis of
the pulse pair Doppler velocity estimation technique discussed in Chap. 5.
Both the cubic and Gaussian power spectral models can be well matched
by a low-order autoregressive (AR, or all-pole) spectrum model of the form
(Haykin et al., 1982)

(2.69)

Real clutter measured from ground-based radars appears to be well matched
using an order N of only two to four. Other studies of clutter measured by
airborne radars in a landing scenario indicate that orders up to 10 may be
required (Baxa, 1991). The AR clutter spectrum model has the advantage that its
parameters can be computed directly from measured data and adapted in real