Design And Implementation Of Software-defined SAR Imaging Component Based On DSP

Synthetic aperture radar(Synthetic Aperture Radar,SAR)is an imaging radar that can overcome weather interference and work all the time.It plays an important role in both military and civilian scenes.In order to solve the problems of high development cost and difficult upgrade and maintenance caused by the customized development mode of SAR imaging system,this thesis designed and developed the SAR imaging algorithm component according to the idea of software-defined radar,so that the SAR imaging application can be realized by component construction to reduce the development difficulty.Firstly,this thesis introduces the basic principle of SAR imaging.This thesis introduces the signal model of SAR imaging and the characteristics of transmitted signal,deduces the principle of classical range Doppler algorithm in SAR imaging algorithm in detail,and investigates the four key steps of range Doppler algorithm: pulse compression,motion compensation,migration correction and azimuth compression.There are two ways of distance compression: matched filtering and linear frequency modulation.As a key issue in airborne SAR imaging,motion compensation also provides two compensation methods.The first is motion compensation based on inertial navigation,and the second is PGA compensation algorithm based on data estimation.Finally,the algorithm principle of range migration and azimuth compression is deduced.Secondly,this paper designs and develops a software SAR imaging algorithm component based on DSP.Firstly,this paper investigates the characteristics of software-defined radar,analyzes the functional requirements of SAR imaging algorithm components,determines that SSDP is the core framework layer and micro xrce-dds is the middleware layer in the whole system,and divides SAR imaging algorithm into four modules for component development.Finally,based on sysbios operating system,SAR imaging algorithm and component control logic are realized on multi-core DSP TMS320C6678.Finally,the function of SAR imaging algorithm component is verified.The correctness of the component data processing results is verified by deriving the algorithm component processing results and MATLAB simulation results.The correctness of the component function is verified by controlling the SAR application through the SSDP display and control interface.Finally,it is concluded that the components designed and developed in this design can normally complete SAR imaging algorithm processing to obtain SAR images.At the same time,as algorithm components,they can also be controllable,adjustable and flexibly deployed.