NonUniformPoissonModel

Nonuniform Poisson birth model

Since R2025a

Description

A NonUniformPoissonModel object contains a birth model that assumes new targets follow a Poisson distribution with a nonuniform birth density. A Poisson distribution of birth is a common assumption in many multi-object tracking algorithms. In this model, you can specify the birth density as a function of measurement, which enables the defining of regions in the measurement space where targets are more likely to appear for the first time. You can use this model to define the birth model for a CustomSensor object.

Creation

To create a NonUniformPoissonModel object, use the sensorBirthModel function with the "nonuniform-poisson" input argument. For example:

birthModel = sensorBirthModel("nonuniform-poisson")

Properties

BirthDensityFcn — Custom function that updates birth density

function handle

Custom function that updates the birth density as a function of measurement and other birth model data, specified as a function handle.

BirthDensityFcn must have one of these signatures:

• density = BirthDensityFcn(z);

• density = BirthDensityFcn(z,data);

z is the measurement reported by the sensor and data is the property ModelData.

Birth density is defined as the number of measurements originating from new targets per unit volume of the measurement space. The volume of measurement space is connected to the measurement model of the sensor. For example, if a radar reports azimuth and range measurements, its birth density can be calculated as a function of measurement:

$$\text{BirthDensity}\left(azimuth,range\right)=\frac{\text{BirthRate}\left(azimuth,range\right)}{\text{AzimuthResolution}\cdot \text{RangeResolution}}$$

The denominator represents the volume of one resolution cell of the radar. The BirthRate (azimuth,range) specifies the average number of new targets appearing in one resolution cell located at (azimuth,range) per update.

ModelData — Additional data to compute birth density

[] (default) | data input for BirthDensityFcn

Additional data to compute the birth density. ModelData can be any MATLAB^® data type, including numeric types, character vectors, cell arrays, structures, and objects.

You can specify this data to define any additional information you require to compute the birth density. To specify additional information, use the function signature density = BirthDensityFcn(z,data) for the BirthDensityFcn property. The ModelData property is sent to the BirthDensityFcn function as its data input argument.

Version History

Introduced in R2025a