AerospaceBistaticRadar

Sensor specification for bistatic radar

Since R2025a

Description

The AerospaceBistaticRadar object contains a sensor specification for a bistatic radar used for aerospace applications. A bistatic radar is a pair of a bistatic emitter and a bistatic receiver positioned at different locations. For more information on the geometry of a bistatic system, see Bistatic Radar Range and Range Rate Measurement. You can use the AerospaceBistaticRadar object as an input sensor specification to multiSensorTargetTracker.

Creation

To create an AerospaceBistaticRadar object, use the trackerSensorSpec function with the "aerospace", "radar", and "bistatic" input arguments. For example:

spec = trackerSensorSpec("aerospace","radar","bistatic")

Properties

General Properties

MeasurementMode — Measurement mode

"range-angle" (default) | "range-only"

Measurement mode of the bistatic radar, specified as "range-angle" or "range-only".

• Specify "range-angle" if the radar reports both range and angle information.

• Specify "range-only" if the radar reports only range information.

Note

An AerospaceBistaticRadar in "range-only" mode cannot initialize Gaussian tracks; it can only update them. To initialize and update tracks with a range-only bistatic radar, use it alongside another sensor capable of initializing Gaussian tracks, such as an AerospaceMonostaticRadar.

Example: "range-only"

MaxNumLooksPerUpdate — Maximum number of looks per update

30 (default) | 1 | positive integer

Maximum number of looks per update, specified as 1 if the sensor is not scanning and as a positive integer greater than 1 if the sensor is scanning.

Example: 40

Data Types: single | double

MaxNumMeasurementsPerUpdate — Maximum number of measurements per update

10 (default) | positive integer

Maximum number of measurements per update, specified as a positive integer.

Example: 10

Data Types: single | double

HasRangeRate — Enable sensor to report target range rate

true (default) | false

Enable sensor to report target range rate, specified as true or false.

Example: true

Data Types: logical

HasElevation — Enable sensor to report target elevation

true (default) | false

Enable the sensor to report target elevation, specified as true or false.

To enable this property, set the MeasurementMode property to "range-angle".

Example: true

Data Types: logical

AzimuthResolution — Azimuth resolution of sensor

1 (default) | positive scalar

Azimuth resolution of the sensor, specified as a positive scalar. The azimuth resolution defines the minimum separation in azimuth angle at which the sensor can distinguish between two targets. Units are in degrees.

To enable this property, set the MeasurementMode property to "range-angle".

Example: 0.3

Data Types: single | double

RangeResolution — Range resolution of sensor

100 (default) | positive scalar

Range resolution of the sensor, specified as a positive scalar. The rage resolution defines the minimum separation in range at which the sensor can distinguish between two targets. Units are in meters.

Example: 30

Data Types: single | double

ElevationResolution — Elevation resolution of sensor

5 (default) | positive scalar

Elevation resolution of the sensor, specified as a positive scalar. The elevation resolution defines the minimum separation in elevation angle at which the sensor can distinguish between two targets. Units are in degrees.

To enable this property, set the HasElevation property to true.

Example: 2.5

Data Types: single | double

RangeRateResolution — Range rate resolution of sensor

10 (default) | positive scalar

Range rate resolution of the sensor, specified as a positive scalar. The range rate resolution defines the minimum separation in range rate at which the sensor can distinguish between two targets. Units are in meters per second.

To enable this property, set the HasRangeRate property to true.

Example: 2.5

Data Types: single | double

DetectionProbability — Probability of detecting target inside the coverage limits

0.9 (default) | scalar in the range (0,1]

Probability of detecting a target inside the coverage limits, specified as a scalar in the range (0, 1].

Example: 0.75

Data Types: single | double

FalseAlarmRate — False alarm report rate

1e-6 (default) | scalar in the range (0,1]

False alarm report rate within each sensor resolution cell, specified as a positive scalar in the range (0,1]. Units are dimensionless. The object determines resolution cells from the AzimuthResolution and RangeResolution properties and, when enabled, from the ElevationResolution and RangeRateResolution properties.

Example: 1e-4

Data Types: single | double

Receiver properties

IsReceiverStationary — Enable stationary mounting receiver

true (default) | false

Enable stationary mounting platform for the receiver, specified as true or false.

• Specify true to use ReceiverPlatformPosition and ReceiverPlatformOrientation to define the receiver platform position and orientation.

• Specify false to use the input data format to define the receiver platform position, velocity, and orientation at any given time. You can use the dataFormat function on the spec object to determine the tracker's input data format.

Example: true

Data Types: logical

ReceiverPlatformPosition — Receiver platform position

[0 0 0] (default) | 1-by-3 real-valued vector

Receiver platform position, specified as a 1-by-3 real-valued vector. Units are in meters. To enable this property, set the IsReceiverStationary property to true.

Example: [-2 0 0.75]

Data Types: single | double

ReceiverPlatformOrientation — Receiver platform orientation

[1 0 0; 0 1 0; 0 0 1] (default) | 3-by-3 real-valued matrix

Receiver platform orientation, specified as a 3-by-3 real-valued rotation matrix. To enable this property, set the IsReceiverStationary property to true.

Example: [1 0 0; 0 0.8660 -0.5000; 0 0.5000 0.8660]

Data Types: single | double

ReceiverMountingLocation — Receiver location on receiver platform

[0 0 0] (default) | 1-by-3 real-valued vector

Receiver location on the Receiver platform, specified as a 1-by-3 real-valued vector of form [x_m y_m z_m]. This property defines the coordinates of the receiver with respect to the receiver platform origin. The default value specifies that the receiver origin is at the origin of its platform. Units are in meters.

Example: [1.25 -0.1 0.8]

Data Types: single | double

ReceiverMountingAngles — Receiver antenna orientation with respect to receiver platform

[0 0 0] (default) | 1-by-3 real-valued vector

Receiver antenna orientation with respect to the receiver platform, specified as a 1-by-3 real-valued vector of form [z_yaw y_pitch x_roll]. Each element of the vector corresponds to an intrinsic Euler angle rotation that carries the body axes of the platform to the receiver axes. The three elements describe the rotations around the z-, y-, and x-axis sequentially. Units are in degrees.

Data Types: single | double

ReceiverFieldOfView — Receiver sensor beam field of view

[60 20] (default) | 1-by-2 real-valued vector

Receiver sensor beam field of view at each look angle, specified as a 1-by-2 real-valued vector of the form [azimuth elevation]. Units are in degrees.

Example: [80 10]

Data Types: single | double

ReceiverRangeLimits — Minimum and maximum detection range of receiver

[0 1e5] (default) | 1-by-2 nonnegative real-valued vector

Minimum and maximum detection range of the receiver, specified as a 1-by-2 nonnegative real-valued vector of the form [Rmin Rmax]. The receiver does not detect targets that are outside this range. The maximum range, Rmax, must be greater than the minimum range, Rmin. Units are in meters.

Example: [0 5e4]

Data Types: single | double

ReceiverRangeRateLimits — Minimum and maximum detection range rate of receiver

[-500 500] (default) | 1-by-2 real-valued vector

Minimum and maximum detection range rate of the receiver, specified as a 1-by-2 real-valued vector of the form [RRmin RRmax]. The receiver does not detect targets that are outside this range rate. To specify a maximum range-rate of RR, use [-RR RR]. Units are in meters per second.

To enable this property, set the HasRangeRate property to true.

Example: [-200 200]

Data Types: single | double

Emitter properties

IsEmitterStationary — Enable stationary mounting emitter

true (default) | false

Enable stationary mounting platform for the emitter, specified as true or false.

• Specify true to use EmitterPlatformPosition and EmitterPlatformOrientation to define the emitter platform position and orientation.

• Specify false to use the input data format to define the emitter platform position, velocity, and orientation at any given time. You can use the dataFormat function on the spec object to determine the tracker's input data format.

Example: true

Data Types: logical

EmitterPlatformPosition — Emitter platform position

[0 0 0] (default) | 1-by-3 real-valued vector

Emitter platform position, specified as a 1-by-3 real-valued vector. Units are in meters. To enable this property, set the IsReceiverStationary property to true.

Example: [-2 0 0.75]

Data Types: single | double

EmitterPlatformOrientation — Emitter platform orientation

[1 0 0; 0 1 0; 0 0 1] (default) | 3-by-3 real-valued matrix

Emitter platform orientation, specified as a 3-by-3 real-valued rotation matrix. To enable this property, set the IsEmitterStationary property to true.

Example: [1 0 0; 0 0.8660 -0.5000; 0 0.5000 0.8660]

Data Types: single | double

EmitterMountingLocation — Emitter location on emitter platform

[0 0 0] (default) | 1-by-3 real-valued vector

Emitter location on the Emitter platform, specified as a 1-by-3 real-valued vector of form [x y z]. This property defines the coordinates of the emitter with respect to the emitter platform origin. The default value specifies that the emitter origin is at the origin of its platform. Units are in meters.

Example: [1.25 -0.1 0.8]

Data Types: single | double

EmitterMountingAngles — Emitter antenna orientation with respect to emitter platform

[0 0 0] (default) | 1-by-3 real-valued vector

Emitter antenna orientation with respect to the emitter platform, specified as a 1-by-3 real-valued vector of form [z_yaw y_pitch x_roll]. Each element of the vector corresponds to an intrinsic Euler angle rotation that carries the body axes of the platform to the emitter axes. The three elements describe the rotations around the z-, y-, and x-axis sequentially. Units are in degrees.

Data Types: single | double

EmitterFieldOfView — Field of view of emitter's sensor beam

[60 20] (default) | 1-by-2 real-valued vector

Field of view of the emitter's sensor beam at each look angle, specified as a 1-by-2 real-valued vector of the form [azimuth elevation]. Units are in degrees.

Example: [80 10]

Data Types: single | double

EmitterRangeLimits — Minimum and maximum range of target that emitter can illuminate

[0 1e5] (default) | 1-by-2 nonnegative real-valued vector

Minimum and maximum range of targets that the emitter can illuminate, specified as a 1-by-2 nonnegative real-valued vector of the form [Rmin Rmax]. The emitter does not detect targets that are outside this range. The maximum range, Rmax, must be greater than the minimum range, Rmin. Units are in meters.

Example: [0 5e4]

Data Types: single | double

EmitterRangeRateLimits — Minimum and maximum detection range rate of target that emitter can illuminate

[-500 500] (default) | 1-by-2 real-valued vector

Minimum and maximum range rate of targets that the emitter can illuminate, specified as a 1-by-2 real-valued vector of the form [RRmin RRmax]. The receiver does not detect targets that are outside this range rate. To specify a maximum range-rate of RR, use [-RR RR]. Units are in meters per second.

To enable this property, set the HasRangeRate property to true.

Example: [-200 200]

Data Types: single | double

Object Functions

dataFormat

Structure for data format required by task-oriented tracker

More About

Data Format Required By Task-Oriented Tracker

After you initialize a tracker, you need sensor data to update the tracker. For a full list of required sensor data and their descriptions, see the table below. See the dataFormat function for details on updating the tracker with sensor data.

Field Name	Description	Comment
ReceiverLookTime	Timestamps of receiver scans, specified as an N-element row vector. N must be smaller than the value specified in the MaxNumLooksPerUpdate property.	None
ReceiverLookAzimuth	Receiver look azimuth angles at ReceiverLookTime, specified as an N-element row vector. Units are in degrees.	None
ReceiverLookElevation	Receiver look elevation angles at ReceiverLookTime, specified as an N-element row vector. Units are in degrees.	Applies only when the HasElevation property is set to true.
ReceiverPlatformPosition	Receiver platform position, specified as a 3-by-N matrix. Each column represents the [x;y;z] platform coordinates at the corresponding ReceiverLookTime. Units are in meters.	Applies only when the IsReceiverStationary property is set to false.
ReceiverPlatformVelocity	Receiver platform velocity, specified as a 3-by-N matrix. Each column represents the [vx;vy;vz] platform velocity at the corresponding ReceiverLookTime. Units are in meters per second.	Applies only when the IsReceiverStationary property is set to false.
ReceiverPlatformOrientation	Receiver platform orientation, specified as a 3-by-3-N matrix. Each 3-by-3 slice represents the rotation matrix at the corresponding ReceiverLookTime. Units are in degrees.	Applies only when the IsReceiverStationary property is set to false.
ReceiverPlatformAngularVelocity	Receiver platform angular velocity, specified as a 3-by-N matrix. Each column represents the [ωx;ωy;ωz] platform angular velocity at the corresponding ReceiverLookTime. Units are in degrees per second.	Applies only when the IsReceiverStationary property is set to false.
EmitterLookAzimuth	Emitter look azimuth angles at ReceiverLookTime, specified as an N-element row vector. Units are in degrees.	None
EmitterLookElevation	Emitter look elevation angles at ReceiverLookTime, specified as an N-element row vector. Units are in degrees.	Applies only when the HasElevation property is set to true.
EmitterPlatformPosition	Emitter platform position, specified as a 3-by-N matrix. Each column represents the [x;y;z] platform coordinates at the corresponding ReceiverLookTime. Units are in meters.	Applies only when the IsEmitterStationary property is set to false.
EmitterPlatformVelocity	Emitter platform velocity, specified as a 3-by-N matrix. Each column represents the [vx;vy;vz] platform velocity at the corresponding ReceiverLookTime. Units are in meters per second.	Applies only when the IsEmitterStationary property is set to false.
EmitterPlatformOrientation	Emitter platform orientation, specified as a 3-by-3-N matrix. Each 3-by-3 slice represents the rotation matrix at the corresponding ReceiverLookTime. Units are in degrees.	Applies only when the IsEmitterStationary property is set to false.
EmitterPlatformAngularVelocity	Emitter platform angular velocity, specified as a 3-by-N matrix. Each column represents the [ωx;ωy;ωz] platform angular velocity at the corresponding ReceiverLookTime. Units are in degrees per second.	Applies only when the IsEmitterStationary property is set to false.
DetectionsTimes	Timestamps of detections, specified as an M-element row vector. M must be smaller than the value specified in the MaxNumMeasurementsPerUpdate property.	None
Azimuth	Detection azimuth angles of observed targets, specified as an M-element row vector. Units are in degrees.	Applies only when the MeasurementMode property is set to "range-angle".
Elevation	Detection elevation angles of observed targets, specified as an M-element row vector. Units are in degrees.	Applies only when the MeasurementMode property is set to "range-angle" and the HasElevation property is set to true.
Range	Detection range to the observed targets, specified as an M-element row vector. Units are in meters.	None
RangeRate	Detection range rate of observed targets, specified as an M-element row vector. Units are in meters per second.	Applies only when the HasRangeRate property is set to true.
AzimuthAccuracy	Standard deviation of azimuth angle measurements, specified as an M-element row vector. Units are in degrees.	Applies only when the MeasurementMode property is set to "range-angle".
ElevationAccuracy	Standard deviation of elevation angle measurements, specified as an M-element row vector. Units are in degrees.	Applies only when the MeasurementMode property is set to "range-angle" and the HasElevation property is set to true.
RangeAccuracy	Standard deviation of range measurements, specified as an M-element row vector. Units are in meters.	None
RangeRateAccuracy	Standard deviation of range rate measurements, specified as an M-element row vector. Units are in meters per second.	Applies only when the HasRangeRate property is set to true.

Tip

To update the tracker at a timestamp when the sensor scan is not complete, specify "LookTime" as empty using zeros(0,1,dataType).

Bistatic Radar Range and Range Rate Measurement

A bistatic radar consists of an emitter and a receiver. The geometry of a bistatic system is illustrated in the figure below. The range measurement reported by the sensor, R_Bistatic, is the difference between the length of the path forming the upper sides of the triangle and the distance between the receiver and the receiver. The range rate of measurement reported by the sensor is the time derivative of R_Bistatic. Thus, the bistatic range can be expressed as:

R_Bistatic = R_E + R_R – L,

where R_E is the range from the emitter to the target, R_R is the range from the target to the sensor, and L, known also as the direct-path or baseline, is the range from the emitter to the receiver.

The emitter-to-target-to-receiver range obtained by the bistatic radar is equal to the sum:

R_E + R_R = 2a.

This sum defines an ellipsoid of constant range. The image shown above describes the ellipsoid when the emitter, receiver, and target lie in the same plane. This results in a 2-D ellipse. The target lies somewhere on the surface of the constant-range ellipsoid with the foci being the emitter and sensor locations, which are separated by the baseline distance L and with a major axis equal to 2a.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

To generate code, you must set the following nontunable properties before setting any other property.

• MeasurementMode

• MaxNumLooksPerUpdate

• MaxNumMeasurementsPerUpdate

• HasElevation

• HasRangeRate

• IsReceiverStationary

• IsEmitterStationary

Version History

Introduced in R2025a