Estimation of atmospheric and transponder survey errors with a navigation Kalman filter

The Completely Integrated Reference Instrumentation System (CIRIS) is an aircraft inertial navigation system (INS) aided with range and range-rate measurements from precisely surveyed ground transponders. The full-ordered Kalman filter `truth´ model for this system is developed with the goal of increasing the error-estimation accuracy of the CIRIS Kalman filter. The authors present the basic structure of the 127-state `truth´ model Kalman filter. The random bias shaping filter model for the transponder positioon survey-errors and the first order Markov shaping filter model for the atmospheric propagation delays are developed. The full-ordered Kalman filter based on the CIRIS `truth´ model is used to process empirical data from a CIRIS flight. The time histories of selected correlated measurement errors´ means, covariances, and range residuals are plotted and analyzed with respect to the filter´s estimate of position and velocity errors, as well as the aircraft trajectory. The initial conclusions drawn from these data are presented