Research On Methods Of Passive Detection And Location Of Micro-UAV Signal

In recent years,for its abundant advantages,micro-unmanned aerial vehicles(micro-UAV)are widely used in so many fields like photography,agriculture,geographical mapping,emergency rescue,etc.However,due to lack way of monitoring and management,a lot of problems are often exposed.For the urgent demand of the monitoring management to micro-UAVs,this dissertation studied the passive detection and location method,in order to implement the detection,direction finding and location of the radio figure transmission signal and remote control signal of micro-UAVs in key areas.In addition,a passive detection and location system for micro-UAVs is developed.The main research contents of this dissertation are as follows:(1)The detection and method for the radio figure transmission signal and remote control signal of micro-UAV was studied.First,through the analysis of the measured micro-UAV signal,the characteristics of UAV signal are summarized.Then,by studying the signal detection method according to its characteristics,a carrier frequency estimation method under low SNR condition based on ZFFT is proposed,which realized rapid and accurate estimation for carrier frequency of UAV signal.What's more,a kind of dynamic threshold pulse detection method suitable for UAV signals is improved,which makes it simpler to measure the amplitude and phase of UAV signal pulse.Finally,the simulation results verify the feasibility and performance of the signal detection algorithm.(2)The uniform circular array(UCA)interferometer direction-finding algorithm for UAV signal is studied.First,the UCA interferometer direction finding model was introduced,and the cause of the phase difference ambiguity is analyzed.Then,the ambiguity resolving method based on amplitude-comparison direction-finding for UCA correlation interferometer was proposed.The feasibility and application condition of this method were analyzed.Thus,the direction-finding algorithm based on ambiguity resolving by amplitude-comparison direction-finding for UCA interferometer is proposed.Finally,through computer simulation,study the influence to ambiguity resolving probability and direction-finding precision of some parameters like SNR and so on.(3)The triangulation locating algorithm for UAV target is studied.First,the multi-station triangulation locating model was established.Then the process of locating by Gauss-Newton iterative algorithm and pseudo-linear least square(PLS)algorithm were introduced,and their advantages and disadvantages were analyzed respectively.And then the multi-initial values Gauss-Newton iterative algorithm based on PLS is proposed,which combines the advantages of previous two algorithms with high precision and acceptable computation.Finally,simulation results verify the performance of the algorithm.(4)A passive detection and location system for micro-UAVs is developed.First,the system design scheme was introduced.And according to the function of each component,the signal processing step is presented.Moreover,the function of the system is summarized.Then,through several groups of real test experiment,study and verify the functions,the direct finding precision and the detection distance of the system.