漂移扫描CCD用于地球同步轨道卫星观测的初步结果

对于地球同步轨道卫星,目前国内主要采用两种观测手段,即小光电望远镜短曝光观测和天文望远镜跟踪恒星(或卫星)观测.事实上,这两种手段都各自存在不足,尤其对于暗弱目标问题更加显著.利用CCD漂移扫描模式和凝视模式相结合观测地球同步轨道卫星具有明显的优势,小口径望远镜(口径约25cm)就能够获得高质量的目标和恒星圆星像与高精度的定位结果.本文重点阐述了获得高精度地球同步轨道卫星光学位置与星等的原理、方法及步骤;最后,利用实测资料的数据处理结果,分析了所获得的地球同步轨道卫星的内部精度及其误差源.

Preliminary Results of GSS' Optical Observation with CCD Drift-scan Mode

There are two main ways for observing GSS(Geo-Stationary Satellite)in China now,that is,short time exposure with small optic-electric telescopes and tracking GSS or reference stars with astronomical telescopes.But,in fact,these two ways have their own disadvantages,specially for fainter objects.There are many obvious advantages that observing GSS and reference stars with stare mode and CCD drift scan mode by turns with small diameter telescope(about 25 cm).This method can obtain not only good circular images of reference stars and GSS but also high precision coordinates of objects.The total internal errors of optical positioning results are better than 0.5as.There are three main parts of internal error source,the local reference system,the system clock,and the mea- surement coordinates of objects.Choosing suitable plate model and obtaining parameters of the chosen plate model and magnitude model of CCD are introduced.The method and the steps for computing high precision optical coordinates of objects are described in detail in this paper.Using actual results of data reduction,precision and source of internal errors are shown and analyzed finally.