1. Application of statistical filter theory to the optimal estimation of position and velocity on board a circumlunar vehicle;Smith;NASA TR R-135,1962
2. Optimal filtering and linear prediction applied to a midcourse navigation system for the circumlunar mission;McLean;NASA TN D-1208,1961
3. A statistical optimizing navigation procedure for space flight;Battin;ARSJ,1962
4. A new approach to linear filtering and prediction problems;Kalman;J. bas. Engng,1960