[3] YANG Y X, GAO W, ZHANG X.Robust Kalman filtering with constraints: a case study for integrated navigation[J].Journal of Geodesy, 2010, 84(6): 373-381.
[4] PAUL A, HARALAMBOUS H, OIKONOMOU C.Characteristics of postmidnight L band scintillation in the transition region from the equatorial to midlatitudes over the Indian longitude sector using COSMIC, C/NOFS, and GPS measurements[J].Radio Science, 2015, 50(12): 1246-1255.