Page 399 - Fundamentals of Radar Signal Processing

FIGURE 5.31 Notional slow-time power spectrum assumed in pulse pair
processing.

(5.100)

The weather peak S (F) is often assumed to be approximately Gaussian shaped
w
and is characterized by its amplitude, mean, and standard deviation. The total
area of the S (F) power spectrum component equals the power of the
w
meteorological echo. PPP is used to estimate the power, mean Doppler shift F ,
0
and variance (commonly called the spectral width) of the weather

component. Each of these can be estimated using either time- or frequency-
domain algorithms, all of which are included under the PPP rubric.
Consider time-domain measurements first. The autocorrelation and power
spectrum of the slow-time data sequence y[m], m = 0, …, M – 1 obtained from
M pulses sampled at a particular range bin are

(5.101)

(5.102)

The power in the slow-time signal can be estimated in the time domain from the
peak of the autocorrelation function

(5.103)

To see how to estimate the mean frequency, ignore the noise for the
moment and assume that the signal component is a pure sinusoid; the power