Study On DBS Imaging Of Missile Borne And Target Detection

With the development and progress of science and technology,and the precision-guided weapon play a more important role in the modern warfare.Because radars have all-day,all-weather,long-range,and other characteristics,they are widely used in the field of precision guidance detection.The missile's radar seeker generally switches between low-resolution search,Doppler beam sharpening,high-resolution synthetic aperture imaging,and high-resolution tracking.This completes the task of finding,aiming,and accurately hitting the targets.DBS is a kind of imaging technology that improves the azimuth resolution by using the Doppler frequency difference,which divides the actual beam into narrower subbeams.It can scan and image the observation area on a large scale,obtain medium-resolution images,and initially screen targets.Because of its advantages such as good real-time performance and low computational load,it has a significant position in civil and military applications.First of all,this article studied the missile-borne DBS technology.Taking the smooth flight phase of missile as an example to establish a DBS signal model of the missile and analyze its working principle in detail.In the context of wide imaging beamwidth and long range of application,in order to expand the application scope of DBS,pulse repetition frequency is designed in consideration of various factors such as azimuth blur,distance blur,pulse occlusion,and altitude clutter.To select the appropriate pulse repetition frequency value,the limitation of the altitude clutter must be abandoned when designing the repetitive frequency.In other words,altitude clutter must be removed by frequency domain operation during signal processing.Therefore,the DBS technology is implemented in this paper using an improved pulse repetition frequency invariant FFT method.Then,the target detection is studied in this article.If the image contains land,only after the land mask pre-treatment is performed,the real target can be found under the interference of other buildings.In this paper,Ostu threshold segmentation method is used to divide the image pixels into two categories to complete the land mask processing.The target is detected by the CFAR,and the features of the target of interest are extracted,such as the average backscattering intensity,area,aspect ratio,etc.Then the robust features are selected as references to eliminate false targets.Finally,the multi-core parallel implementation of missile-borne DBS and target detection algorithm based on TMS320C6678 platform is studied in this article.TMS320C6678 is a high-performance signal processor with high calculation speed,high processing precision and abundant system resources.It can meet the current signal processing requirements of radar signal processing and has been widely used in various radar systems.This article designed the multi-core parallel implementation of the imaging and target detection algorithm in the data flow mode,analyze the distribution of system resources and the key technologies in the engineering implementation process,and verify the effectiveness and feasibility of the algorithm.