Research On Electromagnetic Simulation Of Radar Imaging

Radar imaging has been found wide applications in fields of the war monitoring and environmental remote sensing. In terms of the back-scattering data from the target, the electromagnetic simulation of radar imaging is of both the important theory significance and the practical application value in the area such as the target identification, stealth and anti-stealth, and target imaging diagnoses. The main contributions are as follows:This research begins with an introduction of radar imaging principle, and a study of the relationship between the radar imaging and the electromagnetic scattering characteristic of target. Based on the actual imaging, an effective approach employing the Physical Optics (PO) technique in combination with the method of equivalent currents (MEC) is presented to study the radar echo signal from the complex target.Secondly, the electromagnetic imaging simulation is done for the turntable models and the synthetic aperture radar respectively. According to the study of imaging theories and algorithms, the rotating target echo signal is obtained by using the steeping frequency scheme, meanwhile, the image of the rotating target is depicted. In addition, accompany with the study of the synthetic aperture radar imaging theories, and a LFM signal is used for the echo from the complex target, the range-Doppler imaging algorithm is adopted to character the electromagnetic imaging of the target.Finally, the thesis concludes with a study of time-frequency analysis in ISAR imaging. A simulation comparison is made among several different time-frequency analysis methods from the perspective of their respective advantages and disadvantages in imaging resolution, the ability to control cross-term, and imaging processing time. Hybridized time-frequency analysis in ISAR imaging is proposed , and this method can improve the imaging performance and enriches the time-frequency imaging algorithm.