Multitarget analysis of CFAR detection of partially-correlated χ2 targets

Abstract

The goal of this paper is to treat the problem of detecting the partially-correlated χ² fluctuating targets with two and four degrees of freedom. We analyze the detection performance in general terms of the more generalized version, which is known as GTM, of the CFAR processors when the operating environment is contaminated with outlying target returns and the radar receiver carries its processing based on post-detection integration of M exponentially correlated pulses. Analytical formulas for the detection and false alarm probabilities are derived, in the absence as well as in the presence of spurious targets which are assumed to be moderately fluctuating following χ² target models. A performance assessment by numerous numerical examples, which has considered the role that each parameter can play in the processor performance, is given. The obtained results show that the processor performance enhances, for weak SNR of the primary target, as the correlation coefficient ρ_s increases and this occurs either in the absence or in the presence of extraneous targets. As the strength of the target return increases, the processor tends to invert its behavior. The well-known Swerling models embrace the correlated target cases in the situation where the correlation among the target returns follows χ² fluctuation models with two and four degrees of freedom and this behavior is common for all GTM based detectors.