Position estimation of three-dimensional radars with bias errors.

In a multiple target tracking system combining several radars, the errors in the radar observation coordinates and in the radar position due to alignment of each radar significantly affect the tracking performance. In this paper it is assumed that the former error is negligible. The difference in the position of an aircraft observed simultaneously by the radars in question is linearly approximated. A method is proposed to estimate the bias error of the relative position in several three-dimensional radars by means of a Kalman filter. When several radars are positioned far away, the reference direction and the absolute horizontal plane of the coordinate axis in reference to each radar are inclined due to the curvature of the earth, so that the bias error estimation accuracy is degraded. The slope of the coordinate axis due to the curvature of the earth is specifically corrected for estimation of the bias error of the relative radar position. Also, by means of simulation, the method is compared with that in which the sea surface altitude of an aircraft is calculated from the observed values (range and elevation angle) and the effect of the inclination of the coordinated axis is corrected. It is shown that the estimation accuracy is improved by 3.7 m for a radar range of 10 km and 19.5 m for 30 km. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(9): 64–74, 2004; Published online in Wiley InterScience (<URL>www.interscience.wiley.com</URL>). DOI 10.1002/ecja.10159 [ABSTRACT FROM AUTHOR]