Post-flight trajectory reconstruction of a maneuvering reentry vehicle from radar measurements
Larry Neale Lillard · Defense Technical Information Center (DTIC) · 1982
A technique for determining the aerodynamic parameters of a maneuvering reentry vehicle (MaRV) from post-flight analysis of radar tracking data was developed. The technique uses a sequential weighted least squares estimator which steps through the data processing batches of data sequentially. The observations consisted of angle and range measurements from a precision tracking radar located in the vicinity of the impact area. A six dimension estimator consisting of three position and three velocity components was designed for estimating the state of the RV during free flight. Two reentry estimators were developed. One, a seven dimension estimator consisting of the six elements of the free-flight estimator plus the ballistic coefficient, was designed to estimate the state during ballistic reentry. The second is the nine element MaRV estimator used once a maneuver is begun. An algorithm based on measurement residual monitoring was developed to switch adaptively from the six- state estimator to the seven-state estimator and then to the nine-state estimator. A series of numerical simulations was performed to validate the technique and its programming. Monte Carlo simulations were used to verify the accuracy of the estimator covariance matrix.