Study Of High Precision And High Resolution Passive Direction Finding Algorithm

The direction finding and location of radiation source has always been a research hotspot.It plays an important role not only in national defense system but also in civil system.In the military application,it can realize the accurate reconnaissance of the enemy radiation source.For civil applications,it can help to obtain useful target information,so as to carry out the corresponding rescue work.Passive direction finding equipment has strong concealment ability and little interference from each other.It includes passive direction finding techniques such as amplitudes,phases and spatial spectrum estimation.Which use than the phase interferometer direction finding technology,high Angle measuring accuracy,simple equipment,applicable to a variety of passive direction finding system and scene;Based on the DOA estimation technology of high resolution,it can estimate the direction of multiple sources at the same time with high resolution,which is suitable for the antenna array of line array,plane array and other types.This thesis focuses on the direction-finding and location technology of radiant sources,and briefly introduces the development history of passive direction-finding and the research status of direction-finding technology.In this thesis,the basic principle of direction finding of the interferometer is expatiated,aiming at the contradiction between the range of nonfuzzy Angle of view and the precision of direction finding,that is,the longer the baseline is,the higher the precision is,but the longer the baseline is,the more fuzzy number is.And emphatically introduces the combination hypothesis more rotational positioning interferometer direction finding algorithm of nonlinear least squares method,the six categories of affecting the positioning algorithm performance error(Angle error,attitude error and TOA measurement error,etc.)by modeling and simulation analysis,finally completed the construction of the software platform and debugging.For high resolution DOA estimation of simultaneous multiple sources,the spatial spectral estimation method is more effective than the phase interferometer.Because of the particularity of array structure and the large number of array elements,this thesis adopts the strategy of array region and subarray synthesis to realize the multi-complex target source direction finding in the upper half of conformal array.In this thesis,aiming at a certain vehicle conformal array,using algorithms such as MUSIC and CAPON,combined with region division,high precision and high resolution direction finding for multi-complex targets is realized.Finally,the feasibility and effectiveness of the proposed algorithm are verified through a large number of computer simulation experiments.