A maneuver in the traditional Kalman Filter is estimated with a straight line model and a lot of process noise. Normally a maneuver is flown as 'coordinated turn', that is an arc with constant angular velocity (turnrate). It is possible to use turnrate as a state-variable in an Extended Kalman Filter (EKF). If the system has only incomplete measurements, like line-of-sights, an EKF is a must. In Air Traffic Control where complete measurements are available the EKF is not welcome. The Interactive Multi Model Kalman Filter uses a bank of Kalman Filters for different Mode-of-Flight models. Typically there is a straight line, a 3/s left-turn and a 3/s right-turn KF in the IMMKF. Unfortunately only a small minority of aircrafts perform 'standard turns'. Most aircraft fly 2/s, 4/s or whatever turns. Furthermore, the IMMKF is expensive in computation. The turnrate estimation in the AMRT (Adrian multi radar tracker) is a very straightforward algorithm. A measurement heading is calculated out of two position informations (plots) as delivered from the sensor, a surveillance radar. With two headings and the time difference one measurement-turnrate can be calculated. The topic goes 'statistical' due to the measurement noise. To get rid of the measurement noise two strategies are used: First, the heading calculation is not done with adjacent plots, but with plots that are n measurement intervals apart. With larger n the 'truth' overcomes more and more the 'noise', but maneuver detection time gets larger, too. The paper shows the methods that were used to find the optimum nf or a given scenario. Second, a 'smoothed turnrate' can be used as input-variable to the Kalman Filter. The paper shows the tested algorithms and the advantages/disadvantages to the position accuracy at the output of the Kalman Filter. The presented turnrate-estimation algorithm is much cheaper in computation then the EKF or IMMKF. Nevertheless it gives the 'good old linear' KF a better coordinated turn maneuver capability.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Turnrate estimation in the Adrian multi radar tracker in PHOENIX


    Contributors:


    Publication date :

    2004


    Size :

    6 Seiten, 2 Bilder, 6 Quellen


    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English