Research On High-Precision Ranging Technology Based On Wideband Radar Phase And Its Application

In recent years,as a hot research subject,the acquisition of micro-motion features for Radar targets has played a more and more important role in the radar community.On the basis of high-precision on half-wavelength level,radar phase ranging has become an effective way to extract micro-motion features.However,there are two challenges of radar phase ranging: the first one is the phase extraction of ambiguous Doppler phase and the second one is the resolution of Doppler phase ambiguity.Therefore,in order to resolve those problems,this paper introduces some phase acquisition methods of ambiguous Doppler phase,proposes two ambiguity resolution algorithms,and implements high-precision distance measurement based on wideband phase in the DSP system.In chapter 1,the theoretical significance and practical value of this paper are introduced firstly.Secondly,the key properties and technical bottlenecks of radar phase ranging are illustrated.Thirdly,the research status of Radar phase ranging in recent years is summarized.Finally,the main contents and framework of this thesis are introduced.Chapter 2 focuses on high-precision phase ranging technology based on envelope migration.The phase models of LFM signal based on Dechirping and matched filter pattern are firstly introduced.Secondly,the phase ranging model is optimized,the relationship between the phase increment and envelope migration is deduced,the ambiguity resolution algorithm based on envelope migration is proposed and the algorithm flowchart is presented.Thirdly,the error sources are analyzed.Finally,the validity of this algorithm is substantiated by simulated and experimental results.Chapter 3 focuses on high-precision phase ranging technology based on CRT-DFI.Firstly,the basic theory and improved algorithms of Chinese reminder theorem are introduced.Secondly,a high-precision ranging model based on the wideband phase is established,the relationship between wideband phase and range increment is deduced,CRT-DFI ambiguity resolution algorithm which consists of phase reconstruction based on CRT and ambiguity resolution based on DFI is proposed to realize high-precision distance measurement,and algorithm flowchart is shown.Finally,the restraint conditions of ambiguity resolution algorithm are deduced and the the validity of the algorithm is verified by the experiment.Chapter 4 focuses on the implementation on DSP of high-precision ranging technology based on wideband phase.Firstly,due to the real-time requirements and memory limit of DSP experimental system,the algorithm is optimized by the extraction of envelope migration based on Zoom-FFT technology and implementation of Ultra-long FFT.Secondly,the restraint conditions of optimized algorithm are deduced and the influences of different radar factors on algorithm performance are analyzed.Finally,the experimental system is established and the algorithm performance is verified based on radar simulation data and radar measured data.Chapter 5 summarizes the main contents and the innovations of this paper,the research deficiencies and the further work are shown.