CFAR adaptive threshold for ESM receiver with logarithmic amplification

摘要

An adaptive threshold with constant false alarm rate (CFAR) property is proposed to be used in a channelized electronic support measures (ESM) system with logarithmic video amplification. For this purpose, two CFAR processors are designed which are in fact modified excision (MEx) and adaptive MEx (AMEx) processors, previously presented by authors, but modified for the logarithmic amplification case. In the case of relatively small variations in the noise power, MEx-LOG/CFAR is proposed. This processor exhibits a good robustness against interfering pulses, which cause the major difficulty in the estimation of noise statistics. In the case of relatively large variations in the noise power, AMEx-LOG/CFAR processor is proposed. Thanks to a feedback loop in its structure, this processor can easily adapt itself with any change in the background noise power to assure the CFAR property and false alarm rate regulation. Furthermore, in the steady state (constant noise power), its detection performance is independent of the noise power. Methods to determine the design parameters of the proposed processors are discussed, and their performance analysis is studied using Monte Carlo simulations.