# trackingCKF

Cubature Kalman filter for object tracking

## Description

The `trackingCKF`

object is a cubature Kalman filter used for
tracking objects that follow a nonlinear motion model or are measured by a nonlinear
measurement model. Use the filter to predict the future location of an object, to reduce noise
in a measured location, or to help associate multiple object detections with their
tracks.

The cubature Kalman filter estimates the uncertainty of the state and the propagation of
that uncertainty through the nonlinear state and measurement equations. There are a fixed
number of cubature points chosen based on the spherical-radial transformation to guarantee an
exact approximation of a Gaussian distribution up to the third moment. As a result, the
corresponding filter is the same as an unscented Kalman filter, `trackingUKF`

, with `Alpha`

= 1, `Beta`

= 0, and
`Kappa`

= 0.

## Creation

### Syntax

### Description

returns a cubature
Kalman filter object with default state transition function, measurement function,
state, and additive noise model.`ckf`

= trackingCKF

specifies the `ckf`

= trackingCKF(transitionFcn,measuremntFcn,state)`StateTransitionFcn`

,
`MeasurementFcn`

, and `State`

properties
directly.

specifies the properties of the Kalman filter using one or more
`ckf`

= trackingCKF(___,Name,Value)`Name,Value`

pair arguments. Any unspecified properties take default
values.

## Properties

## Object Functions

`predict` | Predict state and state estimation error covariance of tracking filter |

`correct` | Correct state and state estimation error covariance using tracking filter |

`correctjpda` | Correct state and state estimation error covariance using tracking filter and JPDA |

`distance` | Distances between current and predicted measurements of tracking filter |

`likelihood` | Likelihood of measurement from tracking filter |

`residual` | Measurement residual and residual noise from tracking filter |

`smooth` | Backward smooth state estimates of tracking filter |

`clone` | Create duplicate tracking filter |

`tunableProperties` | Get tunable properties of filter |

`setTunedProperties` | Set properties to tuned values |

`setMeasurementSizes` | Sets the sizes of the measurement and measurement noise |

## Examples

## References

[1] Arasaratnam, Ienkaran, and Simon
Haykin. "*Cubature kalman filters.*" IEEE Transactions on automatic
control 54, no. 6 (2009): 1254-1269.

## Extended Capabilities

## Version History

**Introduced in R2018b**