[1] Cooper D D. Statistical analysis of position-fixing general theory for systems with Gauss errors[J]. PIEE, 1972, 119(6): 637~640.
[2] Gordon T Haupt, Jeremy Kasdin. Optimal recursive iterative algorithm for discrete nonlinear least-squares estimation[J]. Journal of Guidance, Control, and Dynamics, 1996, 19(3): 643~649.