Comments on "A chi-square test for fault detection in Kalman filters" [with reply]

A few errors of omission in the failure-detection application of the above-titled paper by Brumback and Srinath (ibid., vol.AC-32, p.552-4, June 1987) are corrected by the commenter. The commenter points out that what the authors claim is an original alternate (chi-square) test for the failure detection as a possible noniterative replacement for the iterative two ellipsoid overlap test has already been proposed and previously published for automated real-time failure detection for decentralized multisensor navigation. The commenter offers some clarification. Comments are made on the representation of eqs. (21)-(23) as the alternative block matrix mechanization equations for the discrete-time evolution of the underlying covariances that are utilized in the two ellipsoid overlap test. The authors reply that they were unaware of the prior publications and further discuss the commenter´s points.<>