A novel method based on comparison using threshold scale for CFAR detectors under environments with conditions of electromagnetic interference

Abstract

Detection of a noisy signal is a complex process. Many radar systems are working in an environment wherethe signal processing parts cannot overcome the effects of interference sources due to their high power. These sources ofconflict may completely erode the signal or may make a mistake in deciding. It may make the return of the echoes of thegoals difficult. To solve this problem, the detector processor can use a new algorithm to estimate noise power and thencan set the threshold in different positions of the cell under test. The proposed algorithm, by differentiating betweenhomogeneous and interference environments in a multitarget structure, selects a set of reference cells that surroundthe cell under test to estimate the unknown noise/clutter and determine the effective threshold. Then, to evaluate theperformance of cell averaging of constant false alarm rate (CA-CFAR), censored mean level detector CFAR (CMLDCFAR), and excision CFAR (EX-CFAR) detectors, we compared threshold, false alarm, and detection probability in termsof different correlation coefficients. The values were obtained using simulation by MATLAB software. The simulationresults show that the excision parameter, by adding to the window of the reference cells that surround the cell undertest, reduces the effects of background noise on the received signal. We conclude from the proposed method that thehybrid detector not only has higher quality detection interactions in heterogeneous environments but also has relativelyless computational complexity than CA-CFAR, CMLD-CFAR, and EX-CFAR detectors.