大视场高精度星敏感器技术研究
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摘要
星敏感器是一种高精度的姿态测量仪器，具有自主导航能力的新一代星敏感器的显著特点是视场大，精度高，体积、质量、功耗不断减小。本论文以新一代星敏感器为研究背景以大视场、高精度为目的，对星敏感器的应用技术进行了研究与探索。
从星光信号能量和系统传输函数理论出发，分析了影响星敏感器的探测能力的各个环节。以信号探测和概率统计为理论基础，对星等探测灵敏度、星等有效范围和星探测概率进行了分析与估算。推导建立了星敏感器探测能力评估模型，编写了评估仿真程序，并进行了仿真计算与分析。
针对克服像元尺寸对测量精度限制的超精度内插细分技术，在建立了星点光斑数学模型的基础上，利用光电统计理论，推导了星点光斑内插细分精度的极限公式。针对星点光斑特性，分析研究了两种内插细分算法，根据算法特性对比，认为矩心算法比较适于星点质心计算。利用误差统计理论，采用数值模拟的方法，分析了各种噪声对矩心法质心计算精度的影响，推导整理了噪声误差模型。
通过对探测能力和测量精度的分析与研究，得出大视场光学系统结构和采用有效降噪技术的大面阵CCD成像系统，可以有效改善星敏感器的探测能力和测量精度。
对满足大视场要求的几种新型光学系统进行了分析对比；着重分析阐述了衍射光学系统特性对提高星敏感器性能的作用；对带有二元光学元件的折衍混合光学系统在星敏感器中的应用进行了实验研究。
阐述分析了CCD的性能参数；在CCD噪声模型的基础上，分析研究了各种CCD噪声产生的机理及其特性；分析了相关双采样技术对CCD噪声的抑制能力；对噪声抑制对系统信噪比的改善进行了分析与计算。
以折衍混合光学系统和大面阵CCD为基础，设计研制了试验星敏感器样机，进行了静态性能测试与观星试验，实验结果证明了理论研究工作。
Star sensor is a high accuracy instrument for attitude determination. The new generation of autonomous star sensor is characteristic with wider FOV and higher accuracy as well as size, mass and power decreasing. The thesis explores the techniques aimed to wider FOV and higher accuracy under the background of the study on the new generation of star sensor.
Analyzes the various infections on the detection ability by researching the star energy and system MTF. Estimates the magnitude sensitivity, magnitude valid range and probability of star capture based on signal detection and probability statistics. Derives and establishes the detection ability evaluation model, compiles the evaluation program and achieves the simulation result.
For the hyper accuracy interpolation technique, which resolves the accuracy limitation of pixel physical size, derives out the star spot interpolation accuracy limitation based on the star spot mathematical model and photoelectric statistics. Two kinds of interpolation algorithms are analyzed and concluded that the centroiding algorithm is better for star spot position estimation. The noise effects on the centroding are analyzed by numeric simulation, educes the noise RMS model.
With the research into the detection ability and estimation accuracy, achieves the conclusion that the wild FOV optical structure and the large area array CCD imaging system, which applied noise filter techniques, can effectively improve the star sensor performances.
Illustrates several wide FOV optical structure forms, the features of diffraction
optics improving the performances of star sensor are demonstrated. A kind of hybrid optics of refraction and diffraction with a BOE is studied in a test star sensor.
The performance parameters of CCD are expatiated. Based on the CCD noise model, analyzes the producing mechanism and features of the CCD noise. The noise elimination ability of CDS technique is analyzed and the improvement of SNR is calculated.
A test star sensor, which based on the hybrid optics of refraction and diffraction with a BOE and the large area array CCD, is designed and developed. The static performances experiments and the star observation are carried out. The experimental results demonstrate the theoretic research work.
从星光信号能量和系统传输函数理论出发，分析了影响星敏感器的探测能力的各个环节。以信号探测和概率统计为理论基础，对星等探测灵敏度、星等有效范围和星探测概率进行了分析与估算。推导建立了星敏感器探测能力评估模型，编写了评估仿真程序，并进行了仿真计算与分析。
针对克服像元尺寸对测量精度限制的超精度内插细分技术，在建立了星点光斑数学模型的基础上，利用光电统计理论，推导了星点光斑内插细分精度的极限公式。针对星点光斑特性，分析研究了两种内插细分算法，根据算法特性对比，认为矩心算法比较适于星点质心计算。利用误差统计理论，采用数值模拟的方法，分析了各种噪声对矩心法质心计算精度的影响，推导整理了噪声误差模型。
通过对探测能力和测量精度的分析与研究，得出大视场光学系统结构和采用有效降噪技术的大面阵CCD成像系统，可以有效改善星敏感器的探测能力和测量精度。
对满足大视场要求的几种新型光学系统进行了分析对比；着重分析阐述了衍射光学系统特性对提高星敏感器性能的作用；对带有二元光学元件的折衍混合光学系统在星敏感器中的应用进行了实验研究。
阐述分析了CCD的性能参数；在CCD噪声模型的基础上，分析研究了各种CCD噪声产生的机理及其特性；分析了相关双采样技术对CCD噪声的抑制能力；对噪声抑制对系统信噪比的改善进行了分析与计算。
以折衍混合光学系统和大面阵CCD为基础，设计研制了试验星敏感器样机，进行了静态性能测试与观星试验，实验结果证明了理论研究工作。
Star sensor is a high accuracy instrument for attitude determination. The new generation of autonomous star sensor is characteristic with wider FOV and higher accuracy as well as size, mass and power decreasing. The thesis explores the techniques aimed to wider FOV and higher accuracy under the background of the study on the new generation of star sensor.
Analyzes the various infections on the detection ability by researching the star energy and system MTF. Estimates the magnitude sensitivity, magnitude valid range and probability of star capture based on signal detection and probability statistics. Derives and establishes the detection ability evaluation model, compiles the evaluation program and achieves the simulation result.
For the hyper accuracy interpolation technique, which resolves the accuracy limitation of pixel physical size, derives out the star spot interpolation accuracy limitation based on the star spot mathematical model and photoelectric statistics. Two kinds of interpolation algorithms are analyzed and concluded that the centroiding algorithm is better for star spot position estimation. The noise effects on the centroding are analyzed by numeric simulation, educes the noise RMS model.
With the research into the detection ability and estimation accuracy, achieves the conclusion that the wild FOV optical structure and the large area array CCD imaging system, which applied noise filter techniques, can effectively improve the star sensor performances.
Illustrates several wide FOV optical structure forms, the features of diffraction
optics improving the performances of star sensor are demonstrated. A kind of hybrid optics of refraction and diffraction with a BOE is studied in a test star sensor.
The performance parameters of CCD are expatiated. Based on the CCD noise model, analyzes the producing mechanism and features of the CCD noise. The noise elimination ability of CDS technique is analyzed and the improvement of SNR is calculated.
A test star sensor, which based on the hybrid optics of refraction and diffraction with a BOE and the large area array CCD, is designed and developed. The static performances experiments and the star observation are carried out. The experimental results demonstrate the theoretic research work.
引文