Research On Super Large Field Of View Optical Imaging Technology Based On Concentric Lens

With the development of optoelectronic imaging technology,in order to obtain larger spatial range and more information on target characteristics,optical remote sensing systems are gradually developing in the direction of super large field of view and multi-spectral detection.Effectively solving the aberration optimization problem of super large field of view imaging and realizing multi-spectral detection is the research focus of optical remote sensing system.In this paper,taking the typical application of ultra-large field of view optical system-ocean water color remote sensing as the research background,aiming on the demand for super large field of view of ocean water color remote sensing,combining with the development trend and the current problems of ocean color remote sensing super large field of view optical system,the concentric multiscale system is studied,and a new super-large field of view distributed multi-focus multiscale optical system based on concentric lens/mirrors is proposed.According to the application spectrum of ocean water color remote sensing,the paper selects the two bands of visible near-infrared and long-wave infrared.In the visible near-infrared band,a distributed multi-focus multiscale system based on concentric lens is proposed;in the long-wave infrared band,a distributed multi-focal multiscale system based on mirrors/concentric double mirrors is proposed.The new system has Characteristics of large field of view of 110°,small residual aberration of the full field of view,uniform imaging,distortion better than 2% and no moving parts.The resolution gap of full field of view is narrowed to less than 50% of the traditional system.The imaging test is carried out on the super-large field of view distributed multi-focal multiscale system based on concentric lens,and the result shows that the optical system has good imaging quality.The paper focuses on distributed multi-focal multiscale optical systems based on concentric lens/mirrors.The main work and innovations are as follows:(1)A super-large field of view distributed multi-focal multiscale system based on concentric lens/mirrors is proposed.The system has Characteristics of large field of view of 110°,distortion better than 2%,subsystem distributed arrangement by field of view,no moving parts and no need for scanning imaging,which is suitable for ocean water color remote sensing optical detection.The problems of traditional multiscale system applied to ocean water color remote sensing,the selection basis of multiscale system,and the strategy of reducing the full field-of-view resolution gap of distributed multifocal system are discussed in detail.(2)An aberration compensation method for distributed multi-focus multiscale system with super large field of view is proposed,which solves the problem of aberration compensation when the diameter of the entrance pupil and the field of view change simultaneously;a parameter optimization method for the system is proposed,which solves the problem that the imaging field and focal length gap between different subsystems is too large.In the aberration method,the central field of view of each subsystem is perpendicular to its entrance pupil surface,the eccentric and tilt of different subsystems compensates for the low-order aberration caused by the off-center position of the field of view and the diameter of the entrance pupil;the optics structure of different subsystems simultaneously compensates for the higher order aberrations caused by the field of view and the diameter of the entrance pupil itself.In the parameter optimization method,the strategy of covering all fields of view with 6 channels and combining pixels is discussed.The focal length difference between channels is reduced to less than 1.5 times,the field of view gap is reduced to less than 6.2°,and the resolution gap has narrowed to less than 50% of the traditional program.(3)A Galileo-type field distributed multi-focal multiscale system based on concentric spherical lens suitable for visible light and near-infrared is constructed;based on the former research,the prototype of distributed imaging based on concentric spherical lens and the imaging test has completed;aiming at the problem of alignment assembly of multiscale system based on concentric lens,a high-precision alignment method is proposed.In the system design,the principle of aberration compensation and parameter solving of concentric lens is discussed in detail,and the difference between the system design process and the traditional multiscale system is pointed out;in the prototype design,the parameter design,imaging quality evaluation,system tolerance analysis,principle prototype manufacturing and imaging test of the prototype system are discussed in detail;in the alignment method,the working principle of the alignment method are discussed in detail,a new high-precision alignment instrument is built,and the auxiliary alignment method based on the alignment instrument is proposed.(4)A distributed multi-focus multiscale optical system based on spherical mirrors is proposed,which constructs a new multiscale system type and extends the multiscale system to the long-wave infrared band.The system uses spherical mirrors or concentric double spherical mirrors as shared components,and three system configurations are constructed for different system types: coaxial deflection field system based on single spherical mirror,eccentric and off-axis system based on single spherical mirror,off-axis and eccentric system based on concentric double spherical mirror.The principles of aberration compensation and parameter solving for the three systems are discussed in detail.The design ideas of the system are summarized.The overall dimensions,imaging performance,engineering implementation and multi-spectral expansion prospects of the systems are compared in detail.eccentric and off-axis system based on concentric double spherical mirrors is considered to be more advantageous.