| With the increase of the number of space remote sensing platforms,the continuous development of high-resolution cameras and SAR technology,the demand for highresolution imaging is also increasing,and the traditional satellite communication method uses microwave as the transmission medium,and the improvement of data transmission capacity and rate has faced difficulties.Satellite laser communication has become an important technical way to build space-based information networks due to the advantages of large communication capacity,high confidentiality,strong antiinterference ability,small size and weight,and low power consumption.In this paper,the analysis of the pointing error of periscope laser communication terminal and the research of correction method are studied.Firstly,the pointing model of the precision heel branch and the advance branch of a project periscope communication terminal is derived,and the pointing model is simulated,secondly,the factors affecting the aiming performance of the optical communication terminal are analyzed,the error model is established,the error model of each error source is simulated with MATLAB,and the sensitivity analysis method is used to analyze the error source,and finally,the installation matrix parameters of the satellite terminal are identified under the condition of considering the internal structure of the terminal and not considering the internal structure of the terminal.The comparison of pointing error before and after correction is simulated in MATLAB.In this way,the aiming accuracy of the laser communication terminal is improved.The main work of this paper is as follows.(1)Firstly,the typical types of satellite laser communication terminals are introduced,the advantages and disadvantages of several types of communication terminals are analyzed,the research on periscope communication terminals is introduced,and the working principle of periscope terminals to establish communication links is introduced,which is divided into capture,aiming and tracking stages.Under ideal error-free conditions,based on geometric optics and multibody system analysis theory,the fine heel branch and advance branch of the periscope terminal of a project are respectively explained,the coordinate system involved in the terminal is explained,and the reflection matrix of different mirrors is analyzed,and the optical axis pointing model of the laser terminal is established,and the optical axis coordinates of the precision tracking branch pointing model hitting the focal plane of the CCD detector are simulated and verified.(2)the error sources of periscope laser communication terminals are analyzed based on the model of the optical axis of periscope laser communication terminals,including azimuth shaft static error,elevation axis static error,azimuth axis 45° mirror angle error and slope angle error,elevation axis 45° mirror angle error and slope angle error,elevation axis 45° mirror angle error and slope angle error,etc.The error matrix of each error source is calculated,and the numerical simulation of these error sources is carried out,and each error source is analyzed by error sensitivity method.(3)Firstly,the analysis of the effect of scan capture increase on scan time is introduced,and the method of quaternion to find the attitude matrix is introduced,the software compensation method is used to deal with the pointing error,the principle of least squares method is introduced,based on the model established in the previous chapter,theoretical simulation verification and the verification of the measured data of the simplified model are carried out,and the least squares method is used to identify the parameters of the mounting matrix of the rotary table based on folding all the error source parameters into the mounting matrix of the rotary table.and MATLAB is used to simulate the identified pointing error.The corrected mounting matrix reduces the pointing error from 6.28 mrad ×2.13 mrad to 3.85 mrad ×2.71 mrad.The range of pointing error has been reduced. |
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