扩展信标非等晕误差理论分析

摘要

Using a special spectral filtering method,the anisoplanatism of expanded beacon in two typical scenes is mod-elled.And the formulae that describe the total expanded anisoplanatic error and different Zernike model components are obtained. Using two typical turbulent outlines,the characteristics of the expanded anisoplanatic error are studied,and the results indicate that:when the dimension of beacon equals to that of the receiver aperture,the expanded and focal coupling anisoplanatic error is minimal,while the high-order components that the piston,tilt and focus components are removed are not minimal.When the high-order components are minimal,the dimension of beacon should be less than that of the receiver aperture.When the beacon expanded angle equals to beacon departure angle,the expanded anisoplanatic error is about 2.2% of the angle anisoplanatic error. Relative to the angle or focal anisoplanatic error,the anisoplanatic error induced by the dimension of beacon is very little.And in many scenes,it can be ignored.%利用 Sasiele等提出的空间谱滤波技术，对两种典型应用场景下扩展信标非等晕性问题进行了建模，获得了扩展信标非等晕误差及其不同Zernike模式分量的理论公式。基于理论模型，分析了两种场景和典型湍流模式下扩展信标非等晕误差及其不同Zernike模式分量的特性，结果表明：信标扩展度与接收系统口径相同时，扩展与聚焦耦合非等晕方差最小，但扩展与聚焦耦合非等晕方差高阶项(去平移、倾斜和离焦)分量并非最小，高阶项分量最小时信标扩展尺度应小于接收系统口径；当信标扩展角与信标偏置角相当时，纯信标扩展非等晕方差约是纯角度非等晕方差的2.2%；相对湍流大气纯角度和纯聚焦非等晕方差，信标扩展导致的湍流大气非等晕是小量，多数情况下可不考虑。