| The space astronomical telescope adopts the staring observation mode,and the staring exposure time determines its deep-space detection capability.The space astronomical telescope can stare and observe for hundreds of seconds.The stability of optical axis pointing during long-time exposure imaging will affect the imaging quality of space astronomical telescopes.Therefore,the space astronomical telescope is equipped with an image stabilization system to ensure the expected detection accuracy and imaging quality of the space astronomical telescope.After the space astronomical telescope detects the jitter of the image point relative to the optical axis of the telescope,the image stabilization system will be activated to control the jitter of the image point relative to the optical axis of the telescope within an acceptable range.This process is called the telescope image stabilization process.During the accuracy test of the ground image stabilization of the space astronomical telescope,it is necessary to provide an infinite dynamic target for it to simulate the relative optical axis shaking between the telescope and the observation target.In order to accurately assess the imaging quality of the space astronomical telescope,the telescope needs to test the image stabilization accuracy of its image stabilization system during the ground setup stage.At present,space astronomical telescope image stabilization test methods mainly include two types: one is a software simulation method,which is computationally intensive and lacks experimental verification;the other is a physical experimental method,which uses a special target generating device combined with a single beam collimation system The telescope provides a disturbance target.However,as the aperture and field of view of space astronomical telescopes continue to increase,a single beam collimation system cannot meet the needs of space telescope image stabilization testing.Therefore,this theory has carried out the research on the synchronous dynamic target simulation method for the space astronomical telescope image stabilization test.The synchronous dynamic target simulation method based on the silicon-based liquid crystal display proposed in the paper is suitable for the image stabilization accuracy test of large-aperture,large-field space telescopes,and has no special requirements for the overall structure of the space telescope.The homologous,mutually collimated and synchronous dynamic target simulation method proposed in the paper requires sufficient space near the focal plane of the space astronomical telescope to synchronize the arrangement of the dynamic target simulation optical path due to its special optical path arrangement,but the dynamic target simulation optical path The design is more flexible.This paper focuses on the needs of space astronomical telescope image stabilization test,and carries out the research on the synchronous dynamic target simulation method.This paper mainly includes the following contents:1.Realize the multi-light path synchronous dynamic target simulation with the silicon-based liquid crystal display.By adding a microscope objective lens in the optical path,the motion resolution of the dynamic target is improved,and the technical problem of image stabilization accuracy test of the space astronomical telescope with multiple fields of view and the guide star located at the edge of the focal plane is solved.The various error sources that affect the simulation accuracy of the dynamic target are analyzed,and an error model is established on this basis.Through a large number of Monte Carlo simulations,the influence of the comprehensive error on the simulation accuracy of the dynamic target is analyzed.The analysis shows that the time resolution of the dynamic target is 200 Hz,the spatial resolution is better than 1?m,the power spectral density simulation accuracy is 0.0112?,and the synchronization accuracy is 0.01?.Satisfy the image stabilization accuracy test requirements of space astronomical telescopes.2.Completed the establishment of the simulation model of the same source,mutual collimation and synchronization dynamic target.The problem of multi-optical path mirroring is solved by adding a field lens to the optical path.The error sources that affect the simulation accuracy of the analog light path of the same source,mutually collimated and synchronized dynamic target are analyzed,and an error model is established.Analysis shows that: the time resolution of the dynamic target is 200 Hz,the spatial resolution is better than 1?m,the power spectral density simulation accuracy is 0.0164?,and the synchronization accuracy is 0.01?.Satisfy the image stabilization accuracy test requirements of space astronomical telescopes3.The design of the verification experiment scheme was carried out,and the optical simulation of the experimental optical path was carried out.At the same time,the similarities and differences between the experimental scheme and the dynamic target simulation model were analyzed,and the errors of each component in the experimental optical path were calibrated.According to the theoretical model of the dynamic target,the simulation analysis of the experimental optical path is carried out,and then the correctness of the theoretical model is verified through the experiment.4.The two synchronous dynamic target models are compared from the perspectives of application scope,dynamic target simulation source,dynamic target spatial resolution improvement method,dynamic target power spectral density simulation accuracy,dynamic target synchronization accuracy,optical path complexity,and optical path complexity..The two synchronous dynamic target simulation models proposed in this paper can not only be used for image stabilization accuracy testing of space astronomical telescopes,but also suitable for image stabilization accuracy testing of aerial cameras,shipborne photoelectric imaging systems,and handheld optical detection systems. |
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