Page 395 - Fundamentals of Radar Signal Processing

FIGURE 5.27 Blind zone map for one PRF formed by combined blind zones in
Doppler and range.

Figure 5.28 shows blind zone maps for a 10-GHz radar having a 10-μs

pulse length and using two PRIs, 100 μs and 120 μs, on successive CPIs. The
range blind zones are not lengthened for near-in clutter. The clutter velocity
spread is assumed to be ±20 m/s. The velocity axis is shown only for positive
velocity; the negative portion of the axis would be its mirror image. Both maps
are shown to the same scale in range and velocity. Notice that the first range
blind zone and the zero-velocity blind zone are the same for any PRF and so
always overlap in all PRFs used. This is not true for their repetitions in range
and Doppler due to the change in periodicity when the PRF is changed. For

example, a target at a velocity of 300 m/s and range of 30 km is blind in both
range and velocity at the 100-μs PRI but is not in a blind zone at the 120-μs PRI.