1. School of Automation, Xi'an University of Posts and Telecommunications,Xian,P.R. China,710072
2. Research Center of Satellite Technology, Harbin Institute of Technology,Harbin,P. R. China,150001
3. Xi'an Satellite Control Center,Xian,P.R. China,710072
4. Shanghai Institute of Satellite Engineering,Shanghai,P. R. China,200000