Application of extended Kalman filtering to tracking of airborne high-speed broadband acoustic sources
William Garth Frazier, Chad M. Williams, Jay E. Williams, Kenneth E. Gilbert · The Journal of the Acoustical Society of America · 2001
A technique for tracking airborne high-speed (subsonic) broadband acoustic sources is presented. This technique is based upon the familiar extended Kalman filter algorithm used in navigation, radar-based tracking, and feedback control applications. In this application, acoustic sensor-to-source bearing measurements from two locations are used to estimate target position, speed, and heading in near real time. In particular, two strategies for compensating the variable delay in obtaining bearing information caused by sound propagation are developed and presented. One of these is based upon a simple linear predictor. While adequate for sources that are not too distant from the acoustic sensors, it is shown to perform inadequately in some longer-range situations. A second approach, based upon reformulating the Kalman filter to work in conjunction with a generalized triangulation algorithm, is shown to be more robust. Advantageous features of employing a Kalman filter approach to tracking problems include the ability to systematically compensate for measurement noise and to accommodate target maneuverability constraints. Application of the technique to data obtained from a highly maneuverable low-flying commercial aircraft are presented and compared to flight path data obtained via the Global Positioning System.