Research On Passive Location And Tracking Technology Based On Doppler Information

Passive reconnaissance localization mainly uses electromagnetic information of target radiation or reflection in the space to locate and track the target.Compared with the active positioning,it has the advantages of wide working frequency,strong concealment,strong anti-interference and survivability.There are many kinds of information that may be used in the positioning process.The time difference,angle and phase difference information have been studied for many years,and the theory is more ripen and has been widely used in practical engineering.Doppler frequency information research is slightly later in the process,but it has a fairly broad development prospect in the future.The main contents of this paper are as follows:First of all,according to the requirements of the project,the model of Doppler information in single station is studied,and the coordinate systems and their mutual relations in single station positioning are discussed.According to the model of the satellite positioning ground target and the model of ground station positioning the target in the air,We put forward two different location mode-Doppler change rate locating and angle/Doppler joint positioning.Through simulation experiments,the positioning errors of the two positioning methods are given.Then,aiming at another practical project,the localization model of ground multi base station positioning target in the air is deeply studied.The influence of different station type,frequency error and baseline length on positioning effect is discussed and summarized.Then,another location method--TDOA/FDOA multi station joint location is analyzed and we make simulation in the end.Next,We analyze the particle swarm algorithm in swarm intelligence is improved and applied to the multi station frequency difference model.The basic principle of the algorithm,the selection of parameters and the process of implementation are discussed.Then the algorithm is verified by simulation.Finally,the Kalman Filter and its extended algorithm,which are commonly used in locating are studied,and the mathematical principles of the two algorithms are introduced.Then,the simulation results of the two algorithms are given and their advantages and disadvantages are compared in the end.In short,this paper studies the model of single satellite locating ground target.At a certain height,the positioning error,which is the maximum distance of satellite detection error,is less than 10 km and it can meet the project target,when we do research in the model of ground observation station locating the air target,in a certain frequency measurement error,the most distant theoretical detection precision is less than 5‰,which also satisfy the project indicators.