Key Technique Research On The Short-range Active Defense System Radar

Short-range active defense system is important in military. Radar in this system shows some charactersitcs different from the long-range type. For its technical improvement, key radar technologies, such as multi-carrier radar signal, distributed multi-input-multi-output (MIMO) linear array and Doppler tolerance expansion method, are reseached on the basis of wideband ambiguity function (WAF) theory in this dissertation. The main contribution of the dissertation is as following:1. Ambiguity function theory analysis1) Based on the definition of WAF, this section proved that the high-speed target delay-scale unbiased estimation not equal to its distance-velocity unbiased estimation. Influence of accumulated time and relative bandwidth on Doppler tolerance of linear frequency modulation (LFM) signal is also discussed in this section.2) From the viewpoint of correlation receiving, the definition of wideband acceleration ambiguity function (WAAF) is given. Influence of accumulated time and relative bandwidth on WAAF is discussed.3) Application of high-order wavelet cumulant is researched and fast algorithm is induced into its calculation.2. Theoretic research on multi-carrier signal wavform and distributed MIMO array1) Multi-carrier radar signal is analyzed in detail in this section. Its child carrier modulation form includes single frequency, LFM and phase modulation. Based on WAF, the characteristics of multi-carrier signal with different modulation form are compared and discussed. Especially, adjacent channel distrubation is analyzed in detail. Ranging image joint algorithm is also proposed in this section.2) Distributed MIMO array is analyzed. Based on distance-velocity-angle ambiguity function, it's characteristics are discussed. Especially, improving method for synthesis antenna directional diagram is analyzed. Ranging image with different array structure is also proposed.3) Based on the analysis of rank K and Neyman-Pearson joint rule, a qausi-optimum joint detection rule is proposed. It is adapt to distributed MIMO array element of noncoherent network composite.3. Performance analysis and leakage suppression technique research for seabased distributed MIMO array radar.1) Seabased distributed MIMO array radar with particular structure and signal...