
132 Filters, Kernels and Fields
FIGURE 4.2
Radar ranging, see Listing 4.2. The upper thre e signals represent reflections
of a frequency modulated radar pulse (chirp) from three g round points lying
close to one another. Their separation in time is proportional to the distances
separating the ground features along the direction of pulse emission, that
is, transverse to the flight direction. The fourth signal is the superposition
actually received. By convolving it with the emitted signal waveform, the
arrival times are resolved (bottom signal). (See color insert.)
4.2 Linear filters
Linear filtering of images in the spatial domain generally involves moving ...