Research On Target Geometric Positioning Method Of Multipath Exploitation Radar

With the rapid development of radar technology,positioning technology plays a major role in the fields of military,rescue,and monitoring.As to complex scenes such as low-altitude and urban areas,the data errors of the radar receiver increase due to the multipath fading,which leads to the performance degradation of the traditional target positioning methods.Most existing methods for reducing errors increase the number of radars,which will lead to an increase in the complexity and cost of the radar system.This paper uses the extra spatial information brought by the multipath component to establish the target geometric positioning model,which locates the target in the multipath environment,improving the target positioning performance and reducing the system cost.The detailed arrangements of the work of this paper is as follows: 1.The traditional positioning methods are analyzed and studied,including time of arrival positioning,time difference of arrival positioning,angle of arrival positioning and received signal strength positioning.The advantages and disadvantages of each positioning method and applicable scenarios are analyzed.Then the paper puts forward the overall idea of the target positioning method in multipath environment.In this paper,the positioning method uses the time of arrival parameter information of each path.Therefore,the factors affecting the estimation error of time of arrival are analyzed by simulation experiments.2.The target geometric positioning method of multipath exploitation radar is studied.In a multipath environment,the signal transmitted by the radar reaches the point target through a certain known reflection surface.At this time,the mirror position of the radar can be equivalent to a virtual radar,and the information such as the virtual radar position is utilized according to the formation mechanism of the virtual radar.This idea is to indirectly "increase" the number of radars.Firstly,This chapter establishes the radar target geometric positioning model,and analyzes the definition rules of virtual radar and the principle of virtual radar-based target positioning from two-dimensional perspective,and verifies it through simulation.Furthermore,this method is extended to three-dimensional space,one of which is the transformation of the coordinate system;the other is to establish a threedimensional target geometric positioning model based on virtual radar.Finally,the influence of the estimation error of time of arrival on the coordinate deviation and distance deviation of the target is analyzed.This model combines the all path delays to optimize the estimation,instead of relying on a single path delay information,so this method improves the positioning performance.The paper verifies the performance of the method by Monte Carlo simulation.3.The target positioning method of the unknown reflectors is studied.Firstly,the signal propagation model of multi-reflection points of multipath targets is established.Then use the auxiliary station to get more first-order multipath time of arrival,convert it into the elliptical constraint of the estimated reflector,and use the Hough transform to find the common tangent of the reflection points,that is,the position of the reflectors,and then the virtual radar position can be determined.Finally,the optimization algorithm is used to match each path with the reflectors.The matching information and the virtual radar position are used to determine the more accurate target position,which is verified by simulation analysis,so that the target positioning problem of the unknown reflectors is solved.