X射线天体源观测时间估计方法

A Method to Estimate the Observable Time of X-ray Sources

空间探测器对X射线天体源的有效观测时间主要受空间环境因素的制约,制约有效观测时间的主要因素包括太阳避免角、地球对源的遮挡及南大西洋异常区等。然而卫星处于一些高粒子本底区域,太阳与地球之间的光照区及视场指向接近地球时,本底水平很高而且难以确定,这些时间的数据也难以使用。利用orbitTools函数库预测轨道,HEAsoft的attitude函数库计算空间环境变量,利用这些空间环境变量对源的观测时间进行估计,并通过与实际观测比较,证明本方法估计的观测时间与实际情况一致。

The observation constraints for astronomical satellite are always restricted by space environment,such as Sun angle constraint,the time occulted by the Earth and the time passing through South Atlantic Anomaly.There are also some time periods,such as the time in high background region,the time when satellite between the Sun and the Earth,and the time when field of view of the satellite is close to the surface of the Earth,which can′t be used for scientific analysis since the background level is very high or the background model is of great uncertainties.In this work,we establish an interface for these variations to estimate observable time of X-ray sources,and use orbitTools library to generate orbital data and HEAsoft′s attitude library to calculate these variations.Compared with the actual observation,the predicted time of this work is consistent well with the time of observed data.