Research On Consistently Imaging In Full Field-of-view With Wide-area And High-resolution Based On Concentric Spherical Lens

Nowadays,photoelectric imaging technology is an important means for information acquisition and Intelligence gathering.However,application of optoelectronic imaging system is restricted in some new fields because of the difficulty in combining large FOV(field-of-view)and high-resolution imaging.Proposal of multi-scale imaging technology solves above-mentioned problems to a certain extent.But this technology has its inherent defect: center and edge imaging resolution is inconsistent.This defect becomes more serious as the system field of view increases.Aiming at the problem of multi-scale imaging technology,this paper is based on the principle of multi-scale imaging and the design of traditional optical system,and adopts design method of multi-focus optical system in different field of view and imaging area.Furthermore,The imaging region is divided into center FOV,transition FOV and edge FOV according to variation of imaging distance corresponding to different field angles in the full FOV,then corresponding optical systems are designed respectively to achieve the purpose of full-field consistent imaging.Finally,this paper studies the system of the whole field of imaging continuity problem and secondary camera array configuration design,especially discusses continuity problem of the intersection of center FOV,transition FOV and edge FOV,to ensure that our system can realize whole FOV imaging without blind angle,and finally determine the layout design of the secondary optical system array.The main content of this paper is as follows:(1)The theory of multi-scale imaging was introduced to explore the restrictive relationship and reason between large field of view imaging and high-resolution imaging.Besides,principle of multi-scale imaging technology is studied and its corresponding system categories are introduced.This kind of technology has the advantage that breaks through the limitation of low performance saturation of large scale system,but inconsistency of imaging resolution at the center edge still restricts its application prospect.(2)We design the concentric primary objective lens of our system on the basis of Gaussian optics and geometrical optics theory,structure of concentered primary objective is selected as double glue-type according to relationship between surface complexity and signal-to-noise ratio.According to resolution requirements,the resolution of central FOV is designed,so do the focal length and FOV of our system.Finally,an optical system with fixed focal length of the central field of view with good imaging quality is optimized.(3)Optic system’s FOV except center part is divided into transition FOV and edge FOV according to the field angle and imaging distance.Secondary cameras in transition area need to have a larger FOV and focal length to make up for sharp decline in resolution between center and edge of the FOV and to ensure that there is no missing FOV.According to geometrical optics calculation,resolution of edge FOV is about two times different from that of central FOV.Therefore,resolution of our optical system at edge FOV should be significantly higher than that of small camera groups at center FOV.An appropriate initial structure is selected for optimization to achieve research goal of resolution consistency in the whole FOV.(4)FOV mosaic is an important factor in multi-scale imaging system and is also the key to achieve large FOV and high resolution imaging.Based on principle of hexagonal mosaic of wide-area high-resolution camera,this paper redesigns mosaic method of central FOV,transition FOV and edge FOV,determines the size and arrangement of tension angle between subsystems,and finally verifies whether transition without omission can be achieved between the three regions.The FOV of our system is about 110°×110°,and radius of dispersive spot at the center FOV is less than 2.2μm,which is close to the size of Airy spot.The radii of the diffuse spot at transition FOV and edge FOV are all less than 2.8μm,and the imaging quality is well.The total number of our subsystems is 396.The system has preliminarily solved the problem of inconsistency in resolution between center and edge,and provided a new solution and idea for wide field and high resolution imaging in the field of calculation imaging.It can be widely used in many fields such as near space detection,key area protection and so on.