1m红外太阳望远镜光电导行系统中像场旋转的分析

Analysis of the Image-Field Rotation in the Auto Guide System of the 1-meter Infrared Solar Telescope of the Yunnan Observatory

云南天文台1m红外太阳望远镜(YNST)光电导行系统是基于检测太阳像在面阵CMOS图像传感器上的偏移量作为反馈控制信号的高精度闭环跟踪系统[1]。由于YNST是一个地平式装置,在太阳像偏移检测量中存在着像场旋转量,为了获取稳定清晰的太阳像,必须对检测量进行消旋[2]才能达到光电导行系统的跟踪要求。根据球面天文学及天体测量学的知识并结合导行镜的光学系统,推导了光电导行系统中像场旋转的变化规律并对其进行模拟分析。

The Auto Guide System of the 1-meter infrared solar telescope YNST is a high-precision feedback tracking system,which is based on the detection of the offset of the solar image on the CMOS Image Sensor Array to set the feedback control signal for the control system.As the YNST is an altazimuth mounting telescope,there is an image-field rotation in the detected offset of the solar image.In order to obtain clear solar image,there is a need to eliminate the image-field rotation to achieve the tracking requirement of the Auto Guide System.In this paper,based on spherical astronomy,astrometry,and the knowledge of the optical system of the guide telescope,we derive and analyze the variation pattern of the image-field rotation.