1. AIAA .L I* ,\ResearchProfessor, Member,AIAAThis research was conducted at the NASA Langley Research Center under the support of NASA Res. Coop. Agreement NCC1-29.
2. Astronautics,Inc., 1980.All rightsreserved. theoretical studies of convergence properties of an extended Kalman filter indicate that that filter i s not very suitable for parameter estimation (ref.4), especially in cases where the a priori values of parameters are not available and the noise statistics are not known. For that reason two approaches separating the state and parameter estimation were recommended, i.e., References