Gravitational field uncertainty modeling for aerospace vehicles

Statistical gravitational modeling concepts and assumptions are reviewed, and four self-consistent gravitational uncertainty models are examined with reference to their performance in predicting inertial system and ballistic missile errors caused by the earth gravity disturbance field. The models discussed are the third-order Markov model, a model proposed by Tscherning and Rapp (1974), the attenuated white noise model, and the STAG model. In particular, consideration is given to the relative effects of the different gravitational models on impact accuracy for a ballistic missile trajectory. Finally, current activities in gravity modeling are briefly discussed.