Analysis Of Factors Affecting The Image Quality Of High-Order Aspherical Aerial Camera

As an optoelectronic device to obtain ground information,aerial camera is widely used in modern warfare,disaster rescue,geological survey,environmental detection and other fields.With the continuous expansion of the application field of aerial cameras,the requirements for image quality of aerial cameras are also more stringent.Therefore,it is of great significance to analyze the influencing factors of the imaging quality of aerial cameras.This paper takes the self-developed high-order aspherical aerial camera as the research object,and analyzes the influence of vibration load,temperature load and the change of the flight attitude of the carrier aircraft on its imaging quality.The main research contents include the following parts:(1)Based on the analysis theory of opto-mechanical integration,analyze the influence of vibration load on the imaging quality of aerial cameras.The finite element model of the aerial camera is established by Hypermesh software,and the dynamic analysis of the aerial camera is carried out by the finite element software NASTRAN.The rigid body displacement of the optical element and the Zernike polynomial coefficient are fitted and calculated by the nodal displacement data obtained after the finite element analysis.The results of the fitting calculation are optically analyzed by the optical software ZEMAX,and the influence of the vibration load on the optical system is obtained.(2)Based on the analysis theory of opto-mechanical integration,analyze the influence of temperature load on the imaging quality of aerial cameras.Steady-state heat conduction analysis and thermoelastic analysis under temperature load were performed on the aerial camera by the finite element software NASTRAN.The rigid body displacement,surface shape accuracy and Zernike polynomial coefficients of the optical element are fitted and calculated through the nodal displacement data obtained after the finite element analysis.The result after fitting and calculation is optically analyzed by the optical software ZEMAX,and the influence of temperature load on the optical system is obtained.(3)Aiming at the influence of the flight attitude change of the carrier aircraft on the image quality of the aerial camera,the homogeneous coordinate transformation method is used to establish the image movement velocity vector model,and the requirements of the image quality on the attitude change accuracy are analyzed.A three-axis stable platform is designed for stable imaging of high-order aspherical aerial cameras,and the statics and dynamics of the three-axis stable platform are analyzed to confirm that the structural strength of the three-axis stable platform meets the design requirements.(4)Carry out in-field and out-field imaging experiments for high-order aspheric aerial cameras,and verify whether the imaging quality meets the design requirements through experiments.Aiming at the problem that the vibration load and temperature load affect the imaging quality of the aerial camera,a vibration test bench and a temperature test bench were built to verify the correctness of the simulation analysis through experiments.A flight attitude simulation experiment platform is built to verify that the three-axis stabilization platform designed in this paper can play a role in stabilizing the imaging performance of the aerial camera.