MODIFIED SPHERICAL COORDINATES FOR RADAR

摘要

The coordinate system for a nonlinear extended Kalman filter is important because nonlinear coupling between different coordinates (or states) can seriously degrade performance. The radar coordinates of range, Doppler, and angles are well suited to modified spherical coordinates because this coordinate system decouples downrange states from crossrange states. Therefore, an inaccurate (or missing) range estimate does not degrade the estimate of the remaining states. This paper shows that a nine-state filter in modified spherical coordinates (MSC) tracks a maneuvering target well. The problem of missing range measurements (due to ECM or using waveforms without range information) is also discussed.