Study Of Scheduling Of VGOS For National Time Service Center

Very Long Baseline Interferometry(VLBI)is a kind of technique of radio astronomy which have been widely used in Geodesy and astronomy since 1960 s.As for our mankind send more and more spacecraft into the universe,the VLBI technique is used for track and navigate the man-made satellites gradually.The traditional antenna of VLBI slew slow due to the large aperture,in addition,there are many troubles have been caused by the equipment aging.These problems make the traditional VLBI technique harder to satisfied the normal observations and navigation of satellites.In this case,the National Time Service Center of Chinese Academy of Science,obey the rules of VLBI2010,start to found the new generation VLBI observation net consists of several small antennas,we call it NTSC VGOS(VLBI Global Observation System).We can use this new VLBI equipment to calculate the Earth Orientation Parameter and determine satellites' orbit.Unfortunately,traditional VLBI can not track the spacecraft without the near-field model.In order to solve this problem,we should optimize the observe schedule first.The backgroud of VLBI scheduling is introduced in the beginning,then we discript the far-field and near-field delay model of VLBI briefly,and in this section,the VGOS of National Time Service Center of Chinese Academy of Sciences is also showed.In addition,the parameters and models are discussed in detail.At last,based on the software of SCHED,SKED and Vie VS,the realization of different kinds of schedules,which fulfill the needs of NTSC VGOS,is showed.The main results are presented as follows:1.Schedule for the model of common observation of radio source combining with the VGOS of NTSC.Based on SCHED,SKED and Vie VS,the parameters and models related to the scan are discussed particularly.2.Combining the trait of GEO satellite,set the schedule for the D-VLBI based on the transformation of satellite's coordinate.To eliminate the system error of our orbit determination system,the D-VLBI method should be uesd;3.Schedule for the geodesy VLBI observation of radio source.Using the SKED and Vie VS software to achieve this goal.This schedule mode is applied to the EOP solution in geodesy VLBI.