Research On Target Three-dimensional Reconstruction Based On ISAR Image Sequences

Inverse Synthetic Aperture Radar(ISAR)imaging achieves the detection and recognition of targets by obtaining two-dimensional high-resolution images of targets,and its characteristics of long-range,all-weather,and all-time make it widely used in various fields.ISAR three-dimensional reconstruction technology is another important and hot research direction in the field of ISAR imaging.If the target can be reconstructed in three dimensions,it will obtain richer information about the target and greatly improve the level of target detection,classification and recognition.This paper focuses on the 3D reconstruction technology based on ISAR image sequences.The main contents of this paper include the following aspects:The first chapter introduces the research background and significance of this article,introduces the more classic ISAR systems at home and abroad,and then introduces the research status of ISAR image feature points and matching and 3D reconstruction of targets based on ISAR image sequences.It reviewed and introduced,and finally introduced the overall research work and arrangement of the paper.The second chapter introduces the two-dimensional imaging process of ISAR.First,the basic principles of ISAR imaging and some commonly used imaging algorithms are introduced,and the mathematical model of 3D to 2D projection imaging of ISAR targets is introduced.Finally,the movement model of the space orbit target is simulated and the ISAR two-dimensional image sequence during its movement is obtained.The aircraft's electromagnetic simulation data is used to obtain the two-dimensional ISAR sequence image of the aircraft target.The third chapter studies the feature point extraction and matching methods of ISAR sequence images,including grid method matching,SIFT algorithm matching,etc.,and proposes a method using SIFT algorithm to match the entire image sequence.In addition,from the perspective of the transformation relationship between images,a matching method based on SIFT algorithm is proposed,and then the transformation relationship between adjacent images is obtained according to the RANSAC method,and then the transformation relationship is used to match the images.Finally,simulation results are given.The fourth chapter mainly studies the 3D reconstruction part after the ISAR image sequence is matched.It mainly introduces the principle of three-dimensional reconstruction of ISAR image sequence using factorization.The problems of the traditional factorization method in the application of ISAR image sequence reconstruction are analyzed.For example,there are fewer feature points in the entire ISAR image sequence,which leads to fewer 3D points reconstructed in the end and low real-time performance.problem.In view of the above situation,a sequential factorization method is introduced.This method only matches and reconstructs two images at a time.Each time a new image is added,reconstruction is performed once,and then each reconstruction is performed.The results are fused and finally the final reconstruction result is obtained.This method can make the reconstruction result more complete and meet the real-time requirements.Finally,simulation results of two reconstruction methods are given and the results are analyzed.The fifth chapter summarizes the main work of the whole paper,considers the deficiencies in the paper,and thinks about the directions that can be improved in the future.