Radar Detection - MATLAB Simulations for Radar Systems Design - page 81

Figure 2.4. Probability of detection versus single pulse SNR, for several
values of

P fa

.

2.4. Pulse Integration

Pulse integration was discussed in Chapter 1 in the context of radar measure-
ments. In this section a more comprehensive analysis of this topic is introduced
in the context of radar detection. The overall principles and conclusions pre-
sented earlier will not change; however, the mathematical formulation and spe-
cific numerical values will change. Coherent integration preserves the phase
relationship between the received pulses, thus achieving a build up in the sig-
nal amplitude. Alternatively, pulse integration performed after the envelope
detector (where the phase relation is destroyed) is called non-coherent or post-
detection integration.

2.4.1. Coherent Integration
In coherent integration, if a perfect integrator is used (100% efficiency), then
integrating pulses would improve the SNR by the same factor. Otherwise,
integration loss occurs which is always the case for non-coherent integration.
In order to demonstrate this signal buildup, consider the case where the radar
return signal contains both signal plus additive noise. The

n P

m th

pulse is