High Spatial Resolution Polarization Imaging’s Error Analysis And Engineering Implementation

Spatial resolution is the ultimate goal of traditional optical remote sensing and polarization remote sensing.With the development of science and technology and the advancement of society,the demand for information is increasing,and the resolution of satellite remote sensing images is now in meters or sub-meters.The traditional optical remote sensing method can provide full-color high-resolution remote sensing images of ground objects,but this method is greatly affected by the background spectrum,which leads to the failure of remote sensing tasks.As a new means of earth observation,polarization remote sensing adds polarization dimension information based on intensity dimension to enrich the target information.Therefore,it is of great significance to make full use of the polarization information in improving the ability of target detection.The authenticity of information is the lofty mission of remote sensing.The polarization remote sensor is a typical measurement system,and then it is an important link to determine the authenticity of information to analyze the factors that affect its measurement accuracy,and then to control and correct it by reasonable engineering methods.Basing on the application requirements of high spatial resolution of remote sensing,the paper mainly completes the following research:(1)A systematic scheme for high spatial resolution polarization imaging is proposed,and the measurement equation of the system is derived.According to the application requirements,the imaging scheme and polarization information acquiring scheme of current space camera are studied in this paper.Firstly,the advantages and disadvantages of each scheme are analyzed and compared.And then the technical solution of long-focus off-axis three-reverse imaging objective lens combined with technical scheme for simultaneous polarization measurement of partial amplitudes is proposed.Finally,the polarization measurement equation of the system is derived by the principle of polarization measurement.(2)Basing on the technical scheme,the influencing factors of the system polarization measurement accuracy are comprehensively analyzed,and detailed error analysis is carried out,and the specific engineering control measures and correction methods are given in this paper.Focusing on the core requirements of imaging quality and polarization measurement accuracy,the effects of factors such as non-ideality of polarization device,residual polarization of imaging objective lens and system noise on polarization measurement accuracy are analyzed.Error analysis is carried out,and finally,the concrete engineering control measures and correction methods are given to guide the implementation of subsequent projects.(3)The engineering of the system is realized,and the mechanical properties and thermal adaptability of the system are theoretically analyzed.In this paper,the detailed optical system design,optical performance evaluation and system error sensitivity analysis are carried out according to the application requirements,which shows that the whole system is easy to be implemented in engineering.Based on the optical design,the main line of ensuring imaging quality and measurement accuracy is still followed,the detailed structure and thermal adaptability design and analysis are carried out,and the overall optical machine structure scheme of the system is given.According to the results of tolerance distribution of the system,the installation scheme and adjustment results of the whole machine are given,and the rationality and feasibility of the design of the optical machine system are verified.The mechanical properties and thermal adaptability of the system are analyzed by the finite element method.The theory shows that the optical-mechanical system can be used in space environment and has excellent performance.(4)The correction method of polarization measurement error of the system is proposed and the performance verification of the laboratory system is completed.Considering the optical devices of the system,the non-ideality of film parameters and the errors introduced in the process of engineer:ing realization,and considering the complexity of the system at the same time,the polarization calibration of the optical machine system is completed by means of calibrating of the measurement matrix directly.Finally,the performance of important parameters such as optical MTF,polarization measurement accuracy of the system is evaluated,and the verification method and verification results are given.The experimental results show that the optical machine system can be used in high spatial resolution polarization remote sensing detection.