Research On Locating And Tracking Technologies Of Single/Multiple ESM Platform

In modern electronic and information warfare environment, compared with active locating methods, the passive location which works without electromagnetic radiation and has strong viability, is becoming an important direction of locating methods. Airborne ESM system that detects solely on bearings has merits such as far distance,self-hiding,good maneuvering ability has high operational value in campaign and important practical significance of tracking and positioning of emitters.This thesis deals with airborne ESM Early Warning System whose target location and tracking mechanism is based solely on bearings, the location and tracking technology of single / multi-ESM platform of fixed target, slow linear motion target and maneuvering target and adaptive trajectory optimization algorithm on tracking objective are studied in this thesis. The main content and innovation are as follows:1) Aiming at the fixed target location and tracking technology of airborne ESM system, total least squares method is discussed at first and its positioning performance is simulated. Then combined with the actual situation that positioning accuracy is largely influenced by the angular accuracy, the residual test method is proposed to weed out the measured azimuth data which has the large error, and the filtering optimization on residual azimuth is achieved. The location and tracking of fixed radiation sources is acquired using total least squares method. Simulations results indicate that the aforementioned method has better positioning accuracy and stability compared to direct use of total least squares method when there are large errors in the azimuth angle measuring.2) Deal with the non-linear tracking problem of slow linear motion target that detects solely on bearings, the basic principles of nonlinear filtering, and commonly used nonlinear filters are discussed and then applied to single-platform and multi-platform tracking on a single target under certain scene. Simulation results show that the Shifted Rayleigh filters have better accuracy and stability.3) Deal with the disadvantage that the pure azimuth location and tracking is largely influent by the relative position between observation platform and the target, trajectory optimization algorithm of adaptive tracking on slow moving target with different number of ESM platforms is proposed in this thesis. The algorithm is based on the criteria that the trace of location covariance matrix reaches its minimum value to estimate the current location of the target, and to determine the ESM platform position that has the highest positioning accuracy to optimization while tracing. Simulation results show that this algorithm has advantages in the positioning performance than ordinary one.4) An interacting multiple model algorithm based on shifted Rayleigh filter is proposed to solve the strong randomness of emitters movement. The simulation on actual target movement is achieved, the problem of maneuvering target tracking is solved using interacting multiple models tracking device of constant velocity model and Singer model. Simulation results indicate that the proposed algorithm can converge when the target has strong maneuver, and this algorithm is more suitable than the others in application of the circumstance of this article. .