PositionModel

Position measurement model

Since R2025a

Description

An PositionModel object contains a measurement model that measures the position of the target in the defined reference frame. The measurement convention is: measurement = position. You can use this model to define the measurement model for a CustomSensor object.

Creation

To create an PositionModel object, use the sensorMeasurementModel function with the "position" input argument. For example:

measurementModel = sensorMeasurementModel("position")

Properties

NumMeasurementDimensions — Measurement dimensions

3 (default) | 1 | 2

Measurement dimensions, specified as a 1, 2, or 3. This property specifies if the measurement is in 1-D, 2-D or 3-D.

Example: 2

OriginPosition — Position of sensor with respect to target state reference frame

zeros(M,1) (default) | M-by-1 real column vector | M-by-N real matrix

Position of the sensor with respect to the target state reference frame, specified as a M-by-1 real column vector or a M-by-N real matrix. M must be the same as the value specified in the NumMeasurementDimensions property. Units are in meters.

• When specified as a M-by-1 real column vector, the OriginPosition takes the form [x;y;z].

• When specified as a M-by-N real matrix, the OriginPosition represents sequential frames. For example, if the sensor is mounted on a tower, and you know both the sensor's mounting position relative to the tower and the tower's position relative to the target frame, you can specify OriginPosition as [sensorMounting towerPosition], where sensorMounting is the sensor's mounting position relative to the tower and towerPosition is the tower's position relative to the target state's reference frame. The number of the frame, N, must be consistent across the OriginPosition and Orientation properties.

Example: [15 20 40]

Orientation — Orientation of sensor with respect to target state reference frame

eye(M) (default) | M-by-M real matrix | M-by-M-by-N real matrix

Orientation of the sensor with respect to the target state reference frame, specified as a M-by-M real matrix or a M-by-M-by-N real matrix. M must be the same as the value specified in the NumMeasurementDimensions property. Units are in degrees.

• When specified as a M-by-M real matrix, the Orientation represents the sensor's orientation relative to the target state reference frame.

• When specified as a M-by-M-by-N real matrix, the Orientation represents sequential frames. For example, if the sensor is mounted on a tower, and you know both the sensor's mounting orientation relative to the tower and the tower's orientation relative to the target frame, you can specify Orientation as cat(3,sensorMountingOrientation,towerOrientation), where sensorMountingOrientation is the sensor's orientation relative to the tower and towerOrientation is the tower's orientation relative to the target state's reference frame. The number of the frame, N, must be consistent across the OriginPosition and Orientation properties.

PositionVariance — Variance of error in position measurement

eye(M) (default) | real-valued M-by-M matrix

Variance of error in position measurement, specified as a real-valued M-by-M matrix. M must be the same as the value specified in the NumMeasurementDimensions property.

Example: 5*eye(3)

Version History

Introduced in R2025a