Ground moving target detection algorithm for monopulse‐SAR based on complex monopulse ratio

• DOI: 10.1049/iet-rsn.2018.5284
• Publication Date: 2018-09-07T02:27:17Z
• Authors: Di Wu; Daiyin Zhu; Mingwei Shen
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology

Monopulse processing has been proved to be an effective way for airborne synthetic aperture radar (SAR)/ground moving target indication. In the monopulse‐SAR system, moving target detection is applied to a complex ratio diagram, referred to as a complex monopulse ratio diagram (CMRD), generated through a pixel‐by‐pixel comparison between the range‐Doppler (RD) spectra obtained from the difference and sum channels. This study examines the statistics of complex monopulse ratio (CMR) in the Gaussian background. Based on the statistics, a new random variable termed normalised CMR (NCMR) is derived by a linear transform to CMR. It is demonstrated that the conditional probability density function of NCMR, under the null hypothesis (H0), is independent of the clutter‐plus‐noise environment. Motivated by this characteristic, a constant false alarm rate detector using the modulus of NCMR as the test statistic is proposed to detect moving targets. The detection performance is evaluated with a closed‐form expression of the probability of false alarm (PFA) derived. Moreover, the construction of the detector is extended to a so‐called multi‐CMRD form to accommodate even higher detection performance. Experimental results from two groups of real data are displayed to validate the statistical analysis and verify the detection performance.