Research And Implementation Of UAV Passive Time Difference Positioning Method

With the lowering of operating thresholds and the improvement of residents’ consumption levels,consumer drones have continued to be popular in recent years,but the resulting "black flying" and "overflying" incidents of drones have also emerged one after another,which has severely affected social development.Therefore,the demand for anti-UAS systems is increasing,and positioning and tracking of UAVs is a key link in anti-UAS systems.Passive time difference positioning method,as an effective method to locate drones,has received extensive attention at home and abroad because of its passive positioning,good concealment and superiority in locating drone operators.This paper focuses on the technology of locating UAVs through passive time difference positioning methods,and combining the signal transmission characteristics of UAVs,optimizes the time delay estimation algorithm in time difference positioning methods,and designs and implements a set of UAVs.Time difference positioning system.The main research work of the thesis is as follows:In this paper,the communication system of UAV is firstly studied.It mainly introduces the communication systems commonly used by consumer drones.The communication links,mathematical models,and characteristic parameters used by the drone’s remote control and image transmission signals are studied,and the actual drone signals are collected.Analyze its time-frequency domain characteristics to provide a basis for the following positioning method research.Then the time difference positioning algorithm for UAV targets is studied.Mainly from the two key technologies of time difference positioning,time delay estimation and position calculation.In terms of time delay estimation,the generalized cross-correlation time delay estimation algorithm is analyzed,and based on the improved PHAT-GCC algorithm,it is optimized,and the efficiency of the algorithm is improved;in terms of position calculation,three kinds of position solution The principle of the algorithm is analyzed in detail,and the performance of the three algorithms is compared through simulation;the factors that affect the positioning accuracy are tested through simulation,and the station deployment proposal for the UAV’s time difference positioning system is given.Finally,the UAV’s time difference positioning system is designed and implemented.Based on the USRP hardware platform and GNU Radio software platform,the UAV’s time difference positioning system was designed and built,and the entire system was implemented,and then the designed positioning system was applied to the actual scene to estimate and analyze the position of the UAV.error.