Lin Zhao was born in 1968. He obtained his M.S. and Ph.D. degrees from Harbin Engineering University and Harbin Institute of Technology in 1989 and 1992, respectively. He now is a professor at College of Automation, Harbin Engineering University. His main research fields are navigation, guidance and control. E-mail: zhaolin@hrbeu.edu.cn Corresponding author.Liang Li was born in 1984. He received his B.S. degree from Harbin University of Commerce in 2007. He has been a master-doctor combined program graduate student in Harbin Engineering University since 2007. His research interests include GPS navigation and integrity monitoring. E-mail: l_liliang @ yahoo.com.cn Ming Sun was born in 1979. He received his B.S. and M.S. degrees from Heilongjiang University and Harbin University of Commerce in 2004 and 2007, respectively. Now he is a Ph.D. candidate in Harbin Engineering University. His research interests are the intelligent algorithms and their applications for navigation. E-mail: snogisunming @ yahoo.com.cn Xiaoxu Wang was born in 1982. He obtained his B.S. and M.S. degrees from Harbin Engineering University in 2004 and 2007, respectively. Now he is a Ph.D. candidate in the College of Automation, Harbin Engineering University. His research interests are nonlinear filtering algorithm and information fusion. E-mail: woyaofly1982@ 163.com