sensorBirthModel

Birth model for custom sensor specification

Since R2025a

Syntax

sbModel = sensorBirthModel(modelName)

Description

sbModel = sensorBirthModel(modelName) creates a prebuilt sensor birth model based on the model name you specif. You can use tab completion to view the available models. You can use this model to define the BirthModel property of a CustomSensor specification.

Examples

Create and Configure Specification for Marine Radar Using CustomSensor Specification

Create a specification for a marine radar. The radar of interest is on top of a stationary tower.

radarPosition = [0;0;35]; % radar's relative position to the tower origin.
towerPosition = [3800;15200;110]; % tower origin location in scenario coordinate.
radarOrientation = [0 1 0;-1 0 0;0 0 1]; % radar's relative orientation to the tower origin.
towerOrientation = [-0.2 0.6 0.7;0.9 0.3 0;-0.2 0.7 -0.6]; % tower orientation in scenario coordinate.
marineRadarSpec = trackerSensorSpec("custom")

marineRadarSpec = 
  CustomSensor with properties:

    MaxNumMeasurements: 32

      MeasurementModel: []
    DetectabilityModel: []
          ClutterModel: []
            BirthModel: []

          UpdateModels: 0

Define the measurement, detectability, clutter, and birth model of the marine radar specification. For measurement, specify that the radar of interest reports the position in the scenario coordinates.

measurementModel = sensorMeasurementModel("position");
measurementModel.OriginPosition = zeros(3,1);
measurementModel.Orientation = eye(3);

For detectability, specify that the radar detects targets within its field of view around a center beam.

detectabilityModel = sensorDetectabilityModel("field-of-view");
detectabilityModel.AzimuthLimits = [-10 10];
detectabilityModel.ElevationLimits = [-15 15];
detectabilityModel.RangeLimits = [0 10000];
detectabilityModel.OriginPosition = cat(2,radarPosition,towerPosition);
detectabilityModel.Orientation = cat(3,radarOrientation,towerOrientation);
detectabilityModel.DetectionProbability = 0.95;

For clutter, specify that the radar assumes a uniform Poisson clutter model, which assumes false measurements or noise (referred to as "clutter") in radar data are uniformly distributed across the observation space.

clutterModel = sensorClutterModel("uniform-poisson");
clutterModel.ClutterDensity = 5e-9;

For birth, specify that the radar assumes a uniform Poisson birth model, which assumes new targets can appear uniformly across the entire observation space.

birthModel = sensorBirthModel("uniform-poisson");
birthModel.BirthDensity = 5e-9;

Configure the marine radar specification using these models.

marineRadarSpec.MeasurementModel = measurementModel;
marineRadarSpec.DetectabilityModel = detectabilityModel;
marineRadarSpec.ClutterModel = clutterModel;
marineRadarSpec.BirthModel = birthModel;

To update the specification based on time or measurement, you can set the UpdateModels property to true and specify the ModelUpdateFcn function handle of the specification. For example, the following model update function allows you to update the radar center beam orientation with time, and update the position variance with measurement.

marineRadarSpec.UpdateModels = true;
marineRadarSpec.ModelUpdateFcn = @updateRadarSpec;
function spec = updateRadarSpec(spec, data)
if ~isempty(data.Time)
    spec.DetectabilityModel.Orientation(:,:,1) = data.TimeVaryingModelData.BeamOrientation;
end
if ~isempty(data.MeasurementTime)
    spec.MeasurementModel.PositionVariance = data.MeasurementVaryingModelData.PositionVariance;
end
end

Input Arguments

modelName — Birth model name

"uniform-poisson" | "nonuniform-poisson"

Birth model name, specified as "uniform-poisson" or "nonuniform-poisson".

Data Types: char | string

Output Arguments

sbModel — Birth model for sensor

object

Birth model for the sensor, returned as one of these objects:

Input Arguments	Target Specification Object
"uniform-poisson"	UniformPoissonModel
"nonuniform-poisson"	NonUniformPoissonModel

You can use the output birth model object to define the BirthModel property of a CustomSensor object.

Version History

Introduced in R2025a