The TrkMeasurementUpdator_xk package

Overview

The TrkMeasurementUpdator_xk package implements the core mathematics for Kalman filter-based track fitters. It provides the calculations to add or remove a measurement to/from the state vector of a track using fast mathematic routines and a simple internal data model. It inherits from two abstract interfaces, Trk::IUpdator and Trk::IPatternParametersUpdator, and implements the following operations:

• addition of a measurement to a (predicted) track states in local coordinates (i.e. the Kalman filter step)
• removal of a measurement from a track state (inverse filter)
• calculation of Chi2/ndf together with the above operation as well as in separate methods
• operates on Trk::LocalParameters of any dimension (1-5) and definition
• operates also on Trk::LocalPosition

If retrieved under the Trk::IUpdator interface, the Trk::KalmanUpdator_xk provides a set of updating-tools for EDM Trk::TrackParameters.
If retrieved under the Trk::IPatternParametersUpdator interface, the Trk::KalmanUpdator_xk provides a set of methods for manipulating Trk::PatternTrackParameters.
The code has been migrated from the xKalman package to this module.

Author

Igor Gavrilenko

References

R. Fruehwirth, Application of Kalman filtering, NIM A262, 446
R. Fruehwirth, et al., Data Analysis Techniques for High-Energy Physics, 2nd ed.

Extra Pages