Statistical characteristics of MST radar echoes and its interpretation

Abstract

As we shall see later, radar backscattering is produced by fluctuations in the refractiva index of the illuminated medium with scale sizes equal to 1/2 the wave length of the electromagnetic probing wave. The fluctuations are a random process, and so are, consequenlly, the signals received by the radar. Both have to be characterized statistically. The power the technique Is basad on the fact that the statistical parameters that define the signal received are relatad to the statistical parameters of the medium. This allows us to remote-sense the medium from the ground. lt is important, then, in arder to understand the technique, to know the statistical ways of characterizing 1) the fluctuations in refractiva index and 2) signals received. The second may be familiar to many of you. Toe first may not. The second is easier to understand since it is a one dimensional process (time). The first is harder, since involves processes in tour dimensions, 3 in space, and 1 in time; on the other hand, it uses extensions of concepts developed originally far one dimension, and should present no difficulties if these ene dimensional concepts are understood.