Radar Performance Research Based On The Radar Code Design

With the increasingly complexity of the modern radar system and the expansion of the scope of application,the requirements of the radar performance are also increasing.The airborne radar possess obvious superiority compared with the ground radars,therefore,this thesis mainly studies the technology of radar code design based on the airborne radar Space-Time-Adaptive-Processing(STAP)and the technology of dimension reduced STAP.In this thesis,first,we introduce the basic principle of radar system and the model of airborne radar system,and we analyze the basic principle of radar space-time adaptive processing in detail.In addition,we present the basic principle and the characteristics of MIMO radar.Then,we analyze the problem of radar code optimization in the presence of colored Gaussian disturbance under the following constraints:a similarity with a prefixed radar code,both the angle estimation accuracy and the estimation accuracies of Doppler frequency,and a robust energy.Both the Space-Time-Adaptive-Processing(STAP)radar and the robust radar energy have been considered simultaneously;in this sense we provide an improvement in radar code design models.Although the resulting optimization problem is a non-convex Quadratically Constrained Quadratic Program(QCQP),we propose a fast and efficient algorithm based on the relaxation of the original problem into a semidefinite program(SDP).Then we assess the performance of the new encoding technique in terms of detection performance,region of achievable Doppler estimation accuracy,and ambiguity function.Numerical simulations suggest that this kind of radar code design achieves a good performance.As the optimum fully STAP has the characteristics of huge data,high computational complexity and difficulty of real-time processing,the scope of its practical application is narrow.In order to improve the engineering practicability,we analyze the dimension-reduced STAP algorithms.Because the understanding of the airborne radar clutter characteristics is the precondition of the dimension-reduced STAP,we summarize the characteristics of radar clutter and then present the classic clutter dimension-reduced STAP method.Then we analyze the performance of the different dimension-reduced STAP methods.