Research On Optimization Of Site Layout For Multi-station TDOA Location And Direct Positioning Determination

With the continuous development of electronic reconnaissance and countermeasure technology,the passive positioning system,which is an effective supplementary means of active radar,has been rapidly developed,moving towards faster positioning speed and higher positioning accuracy.This paper focuses on the basic principles of multi-station time difference positioning methods,multi-station time difference positioning error analysis,multi-station time difference positioning site layout analysis,and the direct positioning determination method based on time delay.Corresponding solutions are proposed for some problems in current passive multi-station time difference positioning methods,and their effectiveness is verified by simulation experiments.The main research contents are summarized as follows:First,this paper introduces the traditional traditional multi-station time difference positioning algorithm,and analyzes the Newton iterative algorithm and Chan algorithm.In order to improve the Newton iterative algorithm commonly used in traditional multi-station time difference positioning algorithm,a multi-station time difference positioning method combined with artificial bee colony algorithm is proposed to solve the problem of setting initial iteration value of Newton iterative algorithm.Get the initial estimated position of the target,and use it as the initial value of the iteration of the Newton iterative algorithm for more accurate position estimation.The positioning GDOP for multi-station time difference positioning is derived,and the main factors affecting positioning accuracy are analyzed.Simulation results show that the proposed positioning method can effectively solve the problem of initial value setting of Newton’s iterative algorithm and can obtain the positioning results robustly.Secondly,a multi-station time difference positioning system and a UAV formation are studied in order to study the influence of the site layout on the influence factors of multi-station time difference positioning accuracy.Combining with the research results of influencing factors of positioning accuracy,it can be known that when the measurement error such as time difference and site are unchanged,it is possible to effectively improve the positioning accuracy of passive time difference positioning by changing the site layout of the UAV formation.This paper proposes an improved salp swarm algorithm,which is applied to optimize the site layout of the UAV formation.By optimizing the site layout of the UAV formation,the average positioning error of the target area is minimized.The simulation results show that this method can improve the accuracy of solving the site optimization problem of UAV formation,and the positioning accuracy of the obtained site layout method is also better than that of the traditional multi-station time difference positioning method.Then,aiming at the shortcomings of the traditional two-step method in passive multistation time difference positioning,such as the loss of information,parameter measurement accuracy limits positioning accuracy and other shortcomings,a direct position determination algorithm based on maximum likelihood estimation is studied,and an improved salp swarm algorithm is used to solve it.This method can reduce the amount of calculation and improve the positioning speed,and can improve the accuracy of multi-station passive positioning under the condition of low signal-to-noise ratio.When performing multi-target passive positioning,the multi-station direct position determination method can effectively avoid the problem of multi-target signal measurement parameter data association during the traditional two-step multi-station time difference positioning process.The simulation results show that,compared with the traditional two-step method for multi-station time difference positioning,this method can effectively improve the positioning accuracy under the condition of low signal-to-noise ratio and avoid the data association work in multi-target positioning.Finally,using the DSP and FPGA architecture,based on the chip TMS320C6678 platform,a multi-station time difference positioning algorithm based on Newton’s iterative algorithm is implemented.The test experiments of the on-chip positioning algorithm verify that the optimized site layout method can effectively improve the positioning accuracy of the multistation time difference positioning system.