CN-122021162-A - Dynamic integrated modeling and imaging performance quantitative evaluation method for space optical camera

CN122021162ACN 122021162 ACN122021162 ACN 122021162ACN-122021162-A

Abstract

The invention relates to a dynamic integrated modeling and imaging performance quantitative evaluation method of a space optical camera, relates to the technical field of aviation optical remote sensing, and solves the technical problems that the traditional integrated analysis method in the prior art depends on data interaction among software tools, and imaging analysis cannot meet the requirement of an imaging system on accurate prediction of dynamic performance. The method comprises the steps of building a structural dynamics state space model, fitting rigid body displacement, building a linear optical model, integrating modeling and analysis and simulating imaging quality. The space optical camera dynamic integrated modeling and imaging performance quantitative evaluation method can realize the dynamic visual axis error solution of the space optical camera, further can simulate and quantify the actual influence of disturbance on the whole imaging quality of the system through the imaging quality, and provides theoretical guidance for the whole design of an optical-mechanical system.

Inventors

LI ZONGXUAN
CHEN RIFAN
REN SHUHUI
TAO SHUPING
PU YONGJIE
YU JIANGTAO

Assignees

中国科学院长春光学精密机械与物理研究所

Dates

Publication Date: 20260512
Application Date: 20260129

Claims (8)

1. The dynamic integrated modeling and imaging performance quantitative evaluation method for the space optical camera is characterized by comprising the following steps of: Step one, building a structural dynamics state space model; establishing a finite element model of an optical machine structure, performing modal analysis, extracting modal data and establishing a structural dynamics state space model; fitting rigid body displacement; selecting a mirror face rigid body displacement fitting node and solving a rigid body displacement fitting matrix; Step three, establishing a linear optical model; Solving a linear optical sensitivity matrix; Integrating modeling and analysis; Establishing a dynamic optomechanical integrated analysis model to solve the dynamic visual axis error of the system; step five, imaging quality simulation; reconstructing a disturbed image, and analyzing the MTF of an image solving system by adopting a blade edge method.
2. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein the method comprises the following steps: The method comprises the steps of establishing a finite element model of an optical-mechanical system, carrying out modal analysis to verify the accuracy of the finite element model, extracting modal data, solving a correlation matrix and establishing a dynamic linear state space model of the optical-mechanical structure.
3. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein in the second step: for the deformation of the mirror surface, all nodes of the mirror surface are extracted and converted into mirror surface sagittal data for fitting; And extracting displacement information of a small number of nodes on the mirror surface for rigid displacement of the mirror surface, and carrying out fitting solution.
4. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein the step two is specifically as follows: Selecting a certain number of rigid body displacement fitting nodes for each optical element in the space camera, and solving a rigid body displacement fitting matrix based on a least square method and a coordinate transformation principle; and (3) solving the transient response of the surface nodes of the optical elements by using the structural dynamics state space model established in the step one, and fitting and solving the rigid body displacement of each optical element.
5. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein the linear optical sensitivity matrix in the third step is: In the formula, The number of the optical elements is indicated, Represent the first First of the optical elements The degree of freedom of the displacement of the one rigid body, Represent the first Optical sensitivity values for the degrees of freedom of the rigid body displacement, The number of the optical element is indicated, Indicating the rigid body displacement number.
6. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein the step four is specifically as follows: And (3) integrating the structural dynamics state space model established in the first step, the rigid body displacement fitting matrix solved in the second step and the linear optical sensitivity matrix obtained in the third step to form a dynamic optical-mechanical integrated analysis model, and analyzing and solving the dynamic visual axis error of the space camera under given disturbance.
7. The method for dynamic integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 1, wherein the fifth step is specifically as follows: Reconstructing a disturbed image under the influence of the dynamic visual axis error calculated in the fourth step by using a two-dimensional interpolation algorithm; and calculating the MTF of the imaging system under the influence of the micro-vibration single factor by adopting a blade edge method.
8. The method for dynamically integrated modeling and quantitative evaluation of imaging performance of a spatial optical camera according to claim 7, wherein the step five is characterized in that the process of calculating the MTF of the imaging system under the influence of the micro-vibration single factor by using a blade edge method comprises the following steps: firstly, extracting a gray level profile of an edge area to construct an edge expansion function; Then, performing first-order differential operation on the ESF curve to obtain a line diffusion function; The MTF response of the disturbed image is then obtained by fourier transforming the LSF.

Description

Dynamic integrated modeling and imaging performance quantitative evaluation method for space optical camera Technical Field The invention relates to the technical field of aviation optical remote sensing, in particular to a dynamic integrated modeling and imaging performance quantitative evaluation method of a space optical camera. Background The space camera is a core component of an aviation optical remote sensing system, and has the advantages of wide coverage range, high revisiting speed, no limitation of geographical conditions and the like, so that the space camera is widely applied to various fields such as resource census, environment monitoring, topographic mapping, atmospheric and ocean observation, military reconnaissance and the like. Along with the development of space observation technology and the continuous improvement of the requirement of space target observation capability, how to ensure the realization of the theoretical resolution of a space telescope becomes a problem that needs to pay attention to the acquisition of high-definition images. In the in-orbit operation stage, the satellite is in a gravity-free state and is extremely easy to be influenced by external force. Micro-vibration caused by disturbance vibration sources in the satellite can influence the stability of an optical system, a light person can lower the resolution of a space camera and blur images, and a heavy person can even paralysis the whole system, so that tasks fail. Under the influence of micro-vibration, each optical element in the optical camera can generate rigid displacement and surface shape distortion, so that the relative position and the surface shape between the optical elements deviate from the initial design state, the vibration of the visual axis of the optical system is caused, and the instantaneous transfer function of the optical system is influenced. The traditional optical-mechanical integrated analysis method is generally based on data interaction among professional analysis tools, firstly, structural dynamic response of each optical element in a space camera is calculated by utilizing finite element analysis software, then node displacement is led into optical-mechanical interface software to fit and solve rigid displacement of an optical surface, and finally, rigid displacement of the optical surface is led into optical analysis software to solve system visual axis errors or wavefront differences. Although mature professional analysis tools have been developed in the fields of optical design, mechanical simulation, thermal analysis and the like, the traditional multidisciplinary integrated analysis method gradually shows inherent limitations along with the increasingly severe requirements of high-precision space telescopes on comprehensive performance indexes. Specifically: The traditional integrated analysis method relies on data interaction among the software tools of the sub-disciplines, and the analysis flow involves multi-discipline independent modeling and cross-platform data conversion, so that the analysis link is long, the calculation efficiency is low, more errors are easily introduced in the multi-model switching process, and the reliability and consistency of the analysis result are seriously affected. At present, imaging analysis for establishing an integrated model by using an existing software tool is mostly static, a telescope is a dynamic process influenced by vibration load, a complete dynamic process is analyzed to comprise a large amount of data processing, the dynamic transfer characteristic of micro vibration is difficult to completely capture only by depending on discrete data interaction between traditional software, and engineering practice requirements of a modern high-resolution imaging system on accurate prediction and control of dynamic performance cannot be met. Disclosure of Invention The invention provides a dynamic integrated modeling and imaging performance quantitative evaluation method for a space optical camera, which aims to solve the technical problem that the traditional integrated analysis method in the prior art depends on data interaction among software tools and imaging analysis cannot meet the requirement of an imaging system on accurate prediction of dynamic performance. In order to solve the technical problems, the technical scheme of the invention is as follows: the dynamic integrated modeling and imaging performance quantitative evaluation method for the space optical camera is characterized by comprising the following steps of: Step one, building a structural dynamics state space model; establishing a finite element model of an optical machine structure, performing modal analysis, extracting modal data and establishing a structural dynamics state space model; fitting rigid body displacement; selecting a mirror face rigid body displacement fitting node and solving a rigid body displacement fitting matrix; Step three, establishing a linear optica