Quickest Recognition Of Genuine And Dummy Warhead Using MIMO Radar

With high precision and highly destructive effects, ballistic missile has already become one of the most powerful weapons in modern warfare. To defend ballistic missile, scholars all over the world have been engaged in the research on ballistic missile for more than 60 years. From those research we know, the trajectory of ballistic warhead covers three phases: boost phase, middle course phase as well as reentry. The movement of the warhead is a composite motion that can be decomposed into translation and micro-motion. In the middle course phase, ballistic missile will release dummy warhead with genuine warhead. However, advanced dummy warhead is extremely similar to genuine warhead, which makes it difficult to distinguish dummy warhead from genuine warhead. This paper engages in the composite movement of the warhead and analyses the micro-motion of the warhead in detail. By using Multi-Input Multi-Output(MIMO) radar to observe the multi-dimensional movement information of the warhead, this paper builds the state space model(SSM) that describes the movement of the warhead.Genuine warhead and dummy warhead have different system parameter in the SSM,based on which, identification of the warhead could be solved by composite hypothesis testing of the SSM parameter. Initially, both genuine and dummy warheads move with the same system parameter, after the separation, genuine warhead moves with the same system parameter due to self-control system. However, dummy warhead moves with different unknown system parameter. Thus identification of the warhead could be transformed into composite hypothesis testing of the system parameter.This paper adopts traditional ideal likelihood ratio test(ILR), general likelihood ratio test(GLR), locally optimum unknown direction test(LOUD) in identification of the warhead. Both one dimensional occasion and multi-dimensional occasion are considered. With the same false alarm probability, the result of LOUD test is more close to ILR test. The processing of LOUD test is much sooner than GLR test.However, the separation time for genuine and dummy warhead is generally unknown. Thus to identify the warhead as soon as possible is important. This paper proposes to identify the warhead as soon as possible by adopting sequential composite hypothesis testing which detects the warhead initially. This paper also proposes sequential locally optimum unknown direction test(SLOUD) test to identify the warhead, and its performance was compared with sequential GLR test(SGLRT), sequential mismatched likelihood ratio test(SMLRT). Both one dimensional occasion and multidimensional occasion were considered. From numerical analysis, we know SLOUD test has superior performance. The processing velocity is much faster than SGLRT. The main work of this paper includes:1. analyzes the feature of micro-motion matrix for swinging, spinning, conning, procession and nutation and build the discreet time state equation under three dimensional radar coordinate system for ballistic warhead.2. by adopting MIMO radar with distributed antennas to observe the movement of the warhead to intensively, this paper builds observation equation.3. identifies the warhead by using the composite binary hypothesis testing of the state transition matrix, ideal likelihood ratio test, GLR test and LOUD test are used to identify the warhead when false alarm possibility is fixed.4. sequential composite hypothesis testing of the state transition matrix is used to identify the warhead as soon as possible, the detection performance of ideal sequential likelihood ratio test, SGLRT and SLOUD test are compared.