Study On Wide-area Imaging And Route Planning Of Airborne Battlefield Surveillance Radar

The airborne battlefield surveillance radar which works in the Ground Moving Target Indication(GMTI)mode can monitor the moving targets in real time.Thus,the moving targets in the long-distance wide-area ground scene are kept under surveillance through azimuthal scanning.The received data obtained in this mode can also be used for wide-area imaging.Therefore,a wide-area ground scene image can be achieved in a short time.Particularly,a higher resolution of the image is obtained compared with the real-beam of the airborne battlefield surveillance radar,providing effective terrain information support in the battle.In this thesis,a novel wide-area DBS image stitching dark stripe correction method is proposed.With the proposed method,the dark stripes which are caused by beam pattern modulation at the overlaps of adjacent beams can be effectively eliminated.Consequently,the image quality is significantly improved.Focused on executing battlefield surveillance tasks,it is required to utilize multiple small aircrafts in stead of the single large aircraft in the future.Therefore,in order to obtain a better coverage over the mission area,the planning of the route for distributed airborne radars' aircrafts is of significance.In this thesis,a route planning method of distributed airborne radars' aircrafts is proposed based on the differential evolution algorithm.The distributed airborne radars can dynamically monitor the mission area when the aircrafts are flying along the route planned by the proposed method.The following provides a brief summary of all the works:1.Firstly,the working principle and the signal model of the airborne battlefield surveillance radar in the wide-area GMTI mode are studied.It offers an insight into the principle of DBS imaging technology and gives the data processing scheme of the DBS imaging in the practical engineering.Besides,the wide-area image obtained by real data processing is analyzed according to the processing scheme.2.Subsequently,the DBS image stitching method based on motion compensation of inertial data is studied and simulations are performed with the real data.In this thesis,after analyzing the causes of dark stripes,a novel wide-area DBS image dark stripes correction method is proposed to correct the irregular dark stripes that affect the image quality after stitching the DBS images.By analyzing the Range-Doppler relationship of the echoes from adjacent beams,a curve which reflects the relationship between the power of the echo of scanning cycle and the Doppler is presented,so that the power of the echo in the regions of dark stripes can be corrected.Moreover,two data processing schemes based on the proposed method are given.With the proposed method,the dark stripes at the overlaps of adjacent beams in the wide-area image which are caused by beam pattern modulation can be effectively eliminated.And the image quality is significantly improved.Simulation results in terms of DBS imaging are provided to verify the effectiveness of the proposed method.3.Finally,the route planning of distributed airborne radars co-monitoring coverage is studied.The maximum monitoring coverage of the mission area dynamically is required for the distributed airborne radars is required,and there is no fixed flight end for radar aircrafts.In this thesis,in order to satisfy these requirements,a mathematical optimization model for distributed airborne radar co-monitoring coverage route planning is proposed.Moreover,based on the differential evolution algorithm,a single-step route planning method of distributed airborne radars' aircrafts is proposed.It can basically fulfill the requirements of distributed airborne radars co-monitoring coverage.Besides,if some of the aircrafts is damaged,the remaining distributed airborne radars will make up for the missing coverage area as soon as possible.However,the planned routes are over the boundary of the mission area and localized occasionally.In order to optimize these two situations,a multi-step route planning method of distributed airborne radars' aircrafts is proposed.Simulation results are provided to verify the effectiveness and superiority of the proposed route planning methods.