Research On The Remote Target Optoelectronic Detecting System Based On Field Of View Stitching

In remote air target measurement,after using the radar to detect the target,the photoelectric imaging system is used to further acquire and track the target to obtain the image information and achieve high-precision measurement of the target.Infrared imaging equipment has been highly valued and widely used in remote target detection due to its good detection capability and all-weather usage.Since that the target is long distance away and its radiation signal that the imaging system received is weak,the photoelectric acquisition and tracking of the target requires the system to image the target at a certain resolution and signal-to-noise ratio.At the same time,due to that there is a certain amount of error in the guidance data provided by radar,it requires that the system's field of view(FoV)could cover a certain field to achieve reliable capture of the target.However,for a single camera,its lens focal length and the coverable FoV are contradictory when the imaging device size and the number of pixels are determined.While expanding the FoV requires reducing the focal length of the lens used by the system,it results in a decrease in the resolution and the signal-to-noise ratio of the target image,so that the working range of the system is reduced.At the current state of the art,due to the small size of a monolithic imaging device,it is difficult to meet both the imaging resolution and the FoV requirement of the system.Therefore,under the condition that the high-resolution imaging of the target can be satisfied,certain means is needed to achieve large FoV capture of the target.In this dissertation,in the application background of an advanced research project about remote target measurement,the large-field remote target photoelectric acquisition technology is studied.A large-field scanning and stitching imaging scheme by controlling the camera to perform cone rotation is proposed,and a large FoV remote target photoelectric acquisition and tracking system is designed based on the scheme.The main contents of the dissertation are summarized as follows:1.Firstly,the engineering application background of remote target photoelectric measurement was introduced,the development status and main technical problems of remote target photoelectric detection,the development history and statue of the infrared imaging detector are analyzed.Finally,the main research contents of this dissertation are brought forward.2.The large FoV imaging technologies applied in different engineering fields were investigated,and the characteristics of different large FoV imaging schemes were analyzed.Then,based on the practice requirements of remote target acquisition and tracking,a large FoV scanning system based on translational cone rotation is proposed.The system realizes large field capture of the target with scanning cameras,and it realizes gaze tracking of the target with fixed camera.For that the target acquisition and tracking functions are integrated into a single system,the function conversion is straightforward and the overall data link is short for the system.So the system is well suited for remote target measurement applications.3.In order to verify the proposed design of the large FoV imaging system and to further understand the technical difficulties involved in the system construction,an experimental prototype platform was built.The specific process is as follows: Firstly,the scheme of the camera's motion control mechanism is designed,and the system structure is designed based on the scheme.Then the system motion control and the camera exposure control process is designed with the DSP2812 chip as the control core.Next,based on the prototype platform,the imaging characteristics of the system were analyzed,and the image processing flow of the system was designed according to the analysis outcome.Finally,the user interface including system control,image acquisition and processing functions was designed based on MATLAB software.When analyzing the image motion characteristics of the scanning camera,for that the size and direction of the scanning cameras' image motion is fixed,it is proposed that using the Wiener filtering algorithm to recover the image,and good results are obtained.4.Experiments were performed with the prototype platform.Firstly,the calibration process of the prototype was designed,and then the infield experiment and the field experiment were carried out after the calibration.The experiment results verified the feasibility of the system design scheme.5.Based on the above system scheme,a large FoV mosaic imaging system based on central cone rotation is proposed,and the system is analyzed with reference to the research process of the system based on translational cone rotation.The motion control structure of the camera is designed,and the imaging characteristics of the system are analyzed based on the structure.Finally,a comparative analysis of the two imaging systems was performed.This dissertation focuses on the design process of the system,and introduces the contents involving optical,mechanical,electronic control and image of the system,it lays a foundation for the engineering development of the actual system.