Implementation of a Target State Estimator for the Air-to-Air Attack Mode of the AFTI/F-16

摘要

This thesis investigated target state estimation techniques for the air-to-air mode of the AFTI/F-16 automated maneuvering and attack system. The target state estimator(TSE) previously developed would not perform to specifications; possible reasons for this poor performance are presented. This study sought to determine: 1) if the Gauss-Markov dynamics model used in the current TSE was adequate for the tracking accuracies specified; 2) if a rotation had to be performed to account for the states being expressed in one frame while measurements were physically made in another. 3) what effect the conventional covariance updates, coupled with the short (16-bit) wordlength of the TSE computers, has on the stability of the Kalman filter. Two filter dynamics models were designed, tested, and compared. Analysis of filter performance revealed that the Gauss-Markov filter dynamics model was an adequate model. Also, the covariance matrix does not have to be rotated into the LOS frame if the measurements are redefined. However, the power performance of the TSE is no doubt caused by the conventional Kalman filter recursions which are inherently unstable.