Helicopter

Target specification for helicopter

Since R2024b

Description

A Helicopter object contains a target specification for a helicopter. You can use the Helicopter object as an input to multiSensorTargetTracker. The target specification defines the state convention for trackers initialized with it. For Helicopter, the output state convention is: [x;vx;y;vy;z;vz], where:

• x, y, and z represent the x-, y-, and z-coordinates in meters.

• vx, vy, and vz represent the velocity components in different directions in meters per second.

Creation

To create a Helicopter object, use the trackerTargetSpec function with the "aerospace", "aircraft", and "helicopter" input arguments. For example:

spec = trackerTargetSpec("aerospace","aircraft","helicopter")

Properties

IsGeographic — Option to enable tracking in geographic scenario

false (default) | true

Since R2026a

Option to enable tracking in a geographic scenario, specified as true or false. For more information, see Tracking Aerospace Targets in Geographic Scenario.

• When this property is true, the output state convention is [latitude;vxLocal;longitude;vyLocal;altitude;vzLocal], where position components latitude, longitude, and altitude are defined in the ECEF (WGS84) coordinate system, in units of [degrees;degrees;meters]. The velocity components vxLocal, vyLocal, and vzLocal are defined in a local NED or ENU coordinate system with an origin at its concurrent location [latitude;longitude;altitude]. You can use the GeographicReferenceFrame property to specify whether the reference frame is NED or ENU. Additionally, any track with an altitude level below zero will be deleted quickly.

• When this property is false, the output state convention is represented in a user-defined reference frame. This user-defined reference frame must be consistent with the definition of the sensor specifications.

Data Types: logical

GeographicReferenceFrame — Reference frame for target motion in geographic scenario

"NED" (default) | "ENU"

Since R2026a

Reference frame for the target motion in a geographic scenario, specified as "NED" (north-east-down) or "ENU" (east-north-up).

• When this property is "NED", the output state convention is [latitude;vNorth;longitude;vEast;altitude;vDown]. The velocity vNorth, vEast, and vDown are measured from a local reference frame with its origin at the object's location [latitude;longitude;altitude]. vNorth and vEast lie within the tangent plane of the Earth's surface, pointing north and east, respectively. vDown is measured perpendicular to this plane, pointing downward into the Earth.

• When this property is "ENU", the output state convention is [latitude;vEast;longitude;vNorth;altitude;vUp]. The velocity vEast, vNorth, and vUp are measured from a local reference frame with its origin at the object's location [latitude;longitude;altitude]. vEast and vNorth lie within the tangent plane of the Earth's surface, pointing east and north, respectively. vUp is measured perpendicular to this plane, pointing away from the Earth.

Example: "ENU"

Data Types: single | double

MaxHorizontalSpeed — Maximum horizontal speed of target

80 (default) | positive scalar

Maximum horizontal speed of the target, specified as a positive scalar. Units are in meters per second.

Example: 90

Data Types: single | double

MaxVerticalSpeed — Maximum vertical speed of target

10 (default) | positive scalar

Maximum vertical speed of the target, specified as a positive scalar. Units are in meters per second.

Example: 15

Data Types: single | double

MaxHorizontalAcceleration — Maximum horizontal acceleration of target

5 (default) | positive scalar

Maximum horizontal acceleration of the target, specified as a positive scalar. Units are in meters per second squared.

Example: 3

Data Types: single | double

MaxVerticalAcceleration — Maximum vertical acceleration of target

1 (default) | positive scalar

Maximum vertical acceleration of the target, specified as a positive scalar. Units are in meters per second squared.

Example: 0.3

Data Types: single | double

Object Functions

hasTrackerInput

Determine whether tracker needs additional input for target specification

More About

Tracking Aerospace Targets in Geographic Scenario

Tracking specifications offer flexibility by allowing the use of arbitrary reference frames for defining track states, provided that the reference frame remains consistent between sensor and target specifications.

In geographic tracking scenarios, it is common to use geodetic reference frames for position (longitude, latitude, altitude) and local NED/ENU reference frames for velocity, orientation, and acceleration. Here, local means the reference frame's origin is at the geodetic position of each data item.

To avoid the need for manual data conversion to a consistent reference frame, you can specify the IsGeographic (since R2026a) and GeographicReferenceFrame (since R2026a) properties of the target and sensor specifications to enable a geographic tracking scenario. The geographic tracking scenario allows the use of geodetic value for position, and local NED/ENU frame for other state variables.

These tables illustrate how geographic tracking scenarios modify the target and sensor specifications.

• Target State Transition Modeling

  Property Settings	Position Reference Frame	Velocity Reference Frame
  IsGeographic = false	User defined.	User defined.
  IsGeographic = True GeographicReferenceFrame = "NED"	ECEF.	Local NED. Local indicates that the origin of the reference frame is at the geodetic position of each data item.
  IsGeographic = True GeographicReferenceFrame = "ENU"	ECEF.	Local ENU. Local indicates that the origin of the reference frame is at the geodetic position of each data item.

• Target Survival Modeling:

  Property Settings	Survival Model	Comments
  IsGeographic = false	Uniform survival rate survival model.	During coasting, track survival does not depend on position.
  IsGeographic = True	Region of interest survival model. An altitude value below zero defines a region in which tracks have a lower probability of survival during prediction.	Tracks are deleted rapidly when their altitude falls below the Earth's surface.

• Sensor Data Formats and Properties:

  Property Settings	Platform Position Reference Frame	Platform Orientation Reference Frame	Platform Angular Velocity Reference Frame (Monostatic Radar Only)	Platform Velocity Reference Frame (Monostatic Radar Only)
  IsGeographic = false	User defined.	User defined.	Platform body.	User defined.
  IsGeographic = True GeographicReferenceFrame = "NED"	Geodetic ([latitude;longitude;altitude]).	Local NED. Local indicates that the origin of the reference frame is at the geodetic position of each data item.	Platform body.	Local NED. Local indicates that the origin of the reference frame is at the geodetic position of each data item.
  IsGeographic = True GeographicReferenceFrame = "ENU"	Geodetic ([latitude;longitude;altitude]).	Local ENU. Local indicates that the origin of the reference frame is at the geodetic position of each data item.	Platform body.	Local ENU. Local indicates that the origin of the reference frame is at the geodetic position of each data item.

Additionally, you can use the Terrain (since R2026a) property of the sensor specifications to provide terrain data, which impacts the computation of detection probability.

Version History

Introduced in R2024b

R2026a: Tracking aerospace targets in geographic scenario

You can use the new IsGeographic and GeographicReferenceFrame properties to enable a geographic tracking scenario. For more information, see Tracking Aerospace Targets in Geographic Scenario