An appropriate impact angle constraint can not only decrease the approaching velocity but also enlarge the effective collision area of hypersonic interception, improving the interception probability. Based on the principle of quasi parallel approaching, the impact angle constraint is converted into line-of-sight angle constraint according to the initial estimation of target velocity and velocity vector. The guidance law with line-of-sight angle constraint is presented via variable structure control. On the basis of qualitative analysis on interception performances, the fuzzy strategy is proposed to generate the appropriate impact angle and weight coefficient of constraint. It is concluded that, the proposed guidance achieves to guide the line-of-sight to close to zero as well as reach the expected impact angle that automatically generated by the fuzzy controller. Moreover, the miss distance and applicability to target information estimation error are satisfied.
Filter Back-Projection(FBP) algorithm is usually used to reproduce the target image based on polar coordinate format data. The traditional method achieves higher imaging resolution by increasing bandwidth and enlarging the target rotation angle. In practical applications, limited echo data can be obtained due to the reasons from the equipment and the detection targets. Spectral estimation algorithms such as Apes has been widely used in Radar imaging, which can obtain complex spectral estimation with more narrow spectral peaks and lower side-lobes compared with FFT methods. Thus, this paper proposes a technique to achieve higher resolution which using spectral estimation instead of the filtering process in FBP. Simulation results show the efficiency and the accuracy of the presented approach.
Currently, high resolution imaging of the space satellite is a popular topic in the field of radar technology. In contrast with regular targets, the satellite target often moves along with its trajectory and simultaneously its solar panel substrate changes the direction toward the sun to obtain energy. Aiming at the imaging problem, a signal separating and imaging approach based on the empirical mode decomposition (EMD) theory is proposed, and the approach can realize separating the signal of two parts in the satellite target, the main body and the solar panel substrate and imaging for the target. The simulation experimentation can demonstrate the validity of the proposed method.