radarDataGenerator

Generate radar detections or track reports

Since R2021a

Description

The radarDataGenerator System object™ generates detections or track reports of targets. You can specify the detection mode of the sensor as monostatic, bistatic, or electronic support measure (ESM) through the DetectionMode property. You can use radarDataGenerator to simulate clustered or unclustered detections with added random noise, and also generate false alarm detections. You can fuse the generated detections with other sensor data and track objects using a radarTracker object. You can also output tracks directly from the radarDataGenerator object. To configure whether targets are output as clustered detections, unclustered detections, or tracks, use the TargetReportFormat property. You can add radarDataGenerator to a Platform and then use the radar in a radarScenario.

Using a single-exponential model, the radar computes range and elevation biases caused by propagation through the troposphere. A range bias means that measured ranges are greater than the line-of-sight range to the target. Elevation bias means that the measured elevations are above their true elevations. Biases are larger when the line-of-sight path between the radar and target passes through lower altitudes because the atmosphere is thicker at these altitudes. See References for more details.

To generate radar detections or track reports:

1. Create the radarDataGenerator object and set its properties.

2. Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

Creation

Syntax

rdr = radarDataGenerator

rdr = radarDataGenerator(id)

rdr = radarDataGenerator(___,scanConfig)

rdr = radarDataGenerator(___,Name,Value)

Description

rdr = radarDataGenerator creates a monostatic radar sensor that reports clustered detections and uses default property values.

rdr = radarDataGenerator(id) sets the SensorIndex property to the specified id.

rdr = radarDataGenerator(___,scanConfig) is a convenience syntax that creates a monostatic radar sensor and sets its scanning configuration to a predefined scanConfig, in addition to any input arguments from previous syntaxes. You can specify scanConfig as 'No scanning', 'Raster', 'Rotator', 'Sector', or 'Custom'. See Convenience Syntaxes for more details on these configurations.

rdr = radarDataGenerator(___,Name,Value) sets Properties using one or more name-value pairs. Enclose each property name in quotes. For example, radarDataGenerator('TargetReportFormat','Tracks','FilterInitializationFcn',@initcvkf) creates a radar sensor that generates track reports using a tracker initialized by a constant-velocity linear Kalman filter.

Properties

Unless otherwise indicated, properties are nontunable, which means you cannot change their values after calling the object. Objects lock when you call them, and the release function unlocks them.

If a property is tunable, you can change its value at any time.

For more information on changing property values, see System Design in MATLAB Using System Objects.

Sensor Identification

SensorIndex — Unique sensor identifier

0 (default) | positive integer

Unique sensor identifier, specified as a positive integer. Use this property to distinguish between detections or tracks that come from different sensors in a multisensor system. Specify a unique value for each sensor. If you do not update SensorIndex from the default value of 0, then the radar returns an error at the start of simulation.

Data Types: double

UpdateRate — Sensor update rate (Hz)

1 (default) | positive real scalar

Sensor update rate, in hertz, specified as a positive real scalar. The reciprocal of the update rate must be an integer multiple of the simulation time interval. The radar generates new reports at intervals defined by this reciprocal value. Any sensor update requested between update intervals contains no detections or tracks.

Data Types: double

Sensor Mounting

MountingLocation — Mounting location of radar on platform (m)

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

Mounting location of the radar on the platform, in meters, specified as a 1-by-3 real-valued vector of the form [x y z]. This property defines the coordinates of the sensor along the x-axis, y-axis, and z-axis relative to the platform body frame.

Data Types: double

MountingAngles — Mounting rotation angles of radar (deg)

[0 0 0] (default) | 1-by-3 real-valued vector of form [z_yaw y_pitch x_roll]

Mounting rotation angles of the radar, in degrees, specified as a 1-by-3 real-valued vector of the form [z_yaw y_pitch x_roll]. This property defines the intrinsic Euler angle rotation of the sensor around the z-axis, y-axis, and x-axis with respect to the platform body frame, where:

• z_yaw, or yaw angle, rotates the sensor around the z-axis of the platform body frame.

• y_pitch, or pitch angle, rotates the sensor around the y-axis of the platform body frame. This rotation is relative to the sensor position that results from the z_yaw rotation.

• x_roll, or roll angle, rotates the sensor about the x-axis of the platform body frame. This rotation is relative to the sensor position that results from the z_yaw and y_pitch rotations.

These angles are clockwise-positive when looking in the forward direction of the z-axis, y-axis, and x-axis, respectively.

Data Types: double

Scanning Settings

ScanMode — Scanning mode of radar

'Mechanical' (default) | 'Electronic' | 'Mechanical and electronic' | 'No scanning' | 'Custom'

Scanning mode of the radar, specified as 'Mechanical', 'Electronic', 'Mechanical and electronic', 'No scanning', or 'Custom'.

ScanMode	Purpose
'Mechanical'	The sensor scans mechanically across the azimuth and elevation limits specified by the MechanicalAzimuthLimits and MechanicalElevationLimits properties. The scan direction increments by the radar field of view angle between dwells.
'Electronic'	The sensor scans electronically across the azimuth and elevation limits specified by the ElectronicAzimuthLimits and ElectronicElevationLimits properties. The scan direction increments by the radar field of view angle between dwells.
'Mechanical and electronic'	The sensor mechanically scans the antenna boresight across the mechanical scan limits and electronically scans beams relative to the mechanical angles across the electronic scan limits. The total field of regard scanned in this mode is the combination of the mechanical and electronic scan limits. The scan direction increments by the field of view angle between dwells.
'No scanning'	The sensor beam points along the antenna boresight defined by the MountingAngles property.
'Custom'	The sensor points the beam in the direction specified by the LookAngle property.

Example: 'No scanning'

MaxAzimuthScanRate — Maximum mechanical azimuth scan rate (deg/s)

75 (default) | nonnegative scalar

Maximum mechanical azimuth scan rate, specified as a nonnegative scalar in degrees per second. This property sets the maximum scan rate at which the sensor can mechanically scan in azimuth. The sensor sets its scan rate to step the radar mechanical angle by the field of view. If the required scan rate exceeds the maximum scan rate, the maximum scan rate is used.

Dependencies

To enable this property, set the ScanMode property to 'Mechanical' or 'Mechanical and electronic'.

Data Types: double

MaxElevationScanRate — Maximum mechanical elevation scan rate (deg/s)

75 (default) | nonnegative scalar

Maximum mechanical elevation scan rate, specified as a nonnegative scalar in degrees per second. The property sets the maximum scan rate at which the sensor can mechanically scan in elevation. The sensor sets its scan rate to step the radar mechanical angle by the field of view. If the required scan rate exceeds the maximum scan rate, the maximum scan rate is used.

Dependencies

To enable this property, set the ScanMode property to 'Mechanical' or 'Mechanical and electronic'. Also, set the HasElevation property to true.

Data Types: double

MechanicalAzimuthLimits — Mechanical azimuth scan limits (deg)

[0 360] (default) | two-element real-valued vector

Mechanical azimuth scan limits, specified as a two-element real-valued vector of the form [azMin azMax], where azMin ≤ azMax and azMax – azMin ≤ 360. The limits define the minimum and maximum mechanical azimuth angles, in degrees, the sensor can scan from its mounted orientation.

Example: [-10 20]

Dependencies

To enable this property, set the ScanMode property to 'Mechanical' or 'Mechanical and electronic'.

Data Types: double

MechanicalElevationLimits — Mechanical elevation scan limits (deg)

[-10 0] (default) | two-element real-valued vector

Mechanical elevation scan limits, specified as a two-element real-valued vector of the form [elMin elMax], where –90 ≤ elMin ≤ elMax ≤ 90. The limits define the minimum and maximum mechanical elevation angles, in degrees, the sensor can scan from its mounted orientation.

Example: [-50 20]

Dependencies

To enable this property, set the ScanMode property to 'Mechanical' or 'Mechanical and electronic'. Also, set the HasElevation property to true.

Data Types: double

ElectronicAzimuthLimits — Electronic azimuth scan limits (deg)

[-45 45] (default) | two-element real-valued vector

Electronic azimuth scan limits, specified as a two-element real-valued vector of the form [azMin azMax], where -90 ≤ azMin ≤ azMax ≤ 90. The limits define the minimum and maximum electronic azimuth angles, in degrees, the sensor can scan from its mounted orientation.

Example: [-50 20]

Dependencies

To enable this property, set the ScanMode property to 'Electronic' or 'Mechanical and electronic'.

Data Types: double

ElectronicElevationLimits — Electronic elevation scan limits (deg)

[-45 45] (default) | two-element real-valued vector

Electronic elevation scan limits, specified as a two-element real-valued vector of the form [elMin elMax], where -90 ≤ elMin ≤ elMax ≤ 90. The limits define the minimum and maximum electronic elevation angles, in degrees, the sensor can scan from its mounted orientation.

Example: [-50 20]

Dependencies

To enable this property, set the ScanMode property to 'Electronic' or 'Mechanical and electronic'. Also, set the HasElevation property to true.

Data Types: double

MechanicalAngle — Current mechanical scan angle

two-element real-valued vector

This property is read-only.

Current mechanical scan angle of radar, specified as a two-element real-valued vector of the form [az el]. az and el represent the mechanical azimuth and elevation scan angles, respectively, relative to the mounted angle of the radar on the platform.

Data Types: double

ElectronicAngle — Current electronic scan angle

two-element real-valued vector

This property is read-only.

Current electronic scan angle of radar, specified as a two-element real-valued vector of the form [az el]. az and el represent the electronic azimuth and elevation scan angles, respectively, relative to the current mechanical angle.

Data Types: double

LookAngle — Current look angle of sensor

two-element real-valued vector

This property is read-only unless ScanMode is specified as 'Custom'.

Current look angle of the sensor, specified as a two-element real-valued vector of the form [az el]. az and el represent the azimuth and elevation look angles, respectively. Look angle is a combination of the mechanical angle and electronic angle, depending on the ScanMode property.

ScanMode	LookAngle
'Mechanical'	MechnicalAngle
'Electronic'	ElectronicAngle
'Mechanical and electronic'	MechnicalAngle + ElectronicAngle
'No scanning'	[0 0]
'Custom'	LookAngle can be set to point the radar beam to a specific azimuth and elevation.

Dependencies

To enable setting this property, set the ScanMode property to 'Custom'. Otherwise, this property is read-only.

BeamShape — Shape of main beam

'Rectangular' | 'Gaussian'

Shape of the main beam of the two-way antenna pattern, specified as 'Rectangular' or 'Gaussian'.

• When set to 'Rectangular', the main beam is assumed to have an idealized rectangular shape with a uniform antenna gain within the half-power beamwidth and a zero gain outside the half-power beamwidth.

• When set to 'Gaussian', the main beam is approximated by an ideal Gaussian antenna pattern with no side lobes. The azimuth and the elevation half-power beamwidths are determined by the corresponding values of the AzimuthResolution and ElevationResolution properties.

The radar main beam is assumed to have the specified beam shape only within the effective field of view. Outside the effective field of view, the two-way antenna pattern is assumed to be zero. When BeamShape is set to 'Gaussian', the field of view in the azimuth and the elevation directions is assumed to be twice the corresponding half-power beamwidth. When BeamShape is set to 'Rectangular', the azimuth and the elevation fields of view are set to be equal to the corresponding half-power beamwidth. When HasScanLoss is true, the azimuth and the elevation half-power beamwidths are adjusted to include beam broadening due to scanning off-broadside. In this case, the half-power beamwidths are determined by the corresponding values of the EffectiveAzimuthResolution and EffectiveElevationResolution properties.

Dependencies

To enable this property, set the ScanMode property to 'Custom'. If the ScanMode property is not set to 'Custom', then the beamshape is rectangular.

Data Types: char | string

EffectiveFieldOfView — Total effective angular field of view

1-by-2 real-valued vector

This property is read-only.

Current effective azimuthal and elevation fields of view, specified as 2-element vector, [azfov, elfov].

• When BeamShape is set to 'Gaussian', EffectiveFieldOfView=2*[AzimuthResolution ElevationResolution].

• When BeamShape is set to 'Rectangular', EffectiveFieldOfView=[AzimuthResolution ElevationResolution].

When HasScanLoss is true, EffectiveFieldOfView includes the effect of beam broadening when the radar is pointed to an off-broadside angle. In that case it is determined by the corresponding values of the EffectiveAzimuthResolution and EffectiveElevationResolution properties. Units are in degrees.

Example: [3,4]

Dependencies

To enable this property, set the ScanMode property to 'Custom'.

Data Types: double

EffectiveAzimuthResolution — Effective azimuth resolution

scalar

This property is read-only.

Current effective azimuthal resolution of the sensor, specified as a scalar. When HasScanLoss is true, EffectiveAzimuthResolution includes the effect of beam broadening when the radar is pointed to an off-broadside angle. At boresight EffectiveAzimuthResolution equals to the value of the AzimuthResolution property. EffectiveAzimuthResolution equals AzimuthResolution for all look angles when the HasScanLoss property is set to false.

Dependencies

To enable this property, set the ScanMode property to 'Custom'.

EffectiveElevationResolution — Effective elevation resolution

scalar

This property is read-only.

Current effective elevation resolution of the sensor, specified as a scalar. When HasScanLoss is true, EffectiveElevationResolution includes the effect of beam broadening when the radar is pointed to an off-broadside angle. At boresight EffectiveElevationResolution equals to the value of the ElevstionResolution property. EffectiveElevationResolution equals ElevstionResolution for all look angles when the HasScanLoss property is set to false.

Dependencies

To enable this property, set the ScanMode property to 'Custom'.

Detection Reporting Specifications

DetectionMode — Detection mode

'Monostatic' (default) | 'ESM' | 'Bistatic'

Detection mode, specified as 'Monostatic', 'ESM', or 'Bistatic'. When set to 'Monostatic', the sensor generates detections from reflected signals originating from a collocated radar emitter. When set to 'ESM', the sensor operates passively and can model ESM and (radar warning receiver) RWR systems. When set to 'Bistatic', the sensor generates detections from reflected signals originating from a separate radar emitter. For more details on detection mode, see Radar Sensor Detection Modes.

Example: 'Monostatic'

HasElevation — Enable radar to scan in elevation and measure target elevation angles

false or 0 (default) | true or 1

Enable the radar to scan in elevation and measure target elevation angles, specified as a logical 0 (false) or 1 (true). Set this property to true to model a radar sensor that can estimate target elevation.

Data Types: logical

HasRangeRate — Enable radar to measure target range rates

false or 0 (default) | true or 1

Enable the radar to measure target range rates, specified as a logical 0 (false) or 1 (true). Set this property to true to model a radar sensor that can measure range rates from target detections.

Data Types: logical

HasNoise — Enable addition of noise to radar sensor measurements

true or 1 (default) | false or 0

Enable the addition of noise to radar sensor measurements, specified as a logical 1 (true) or 0 (false). Set this property to true to add noise to the radar measurements. Otherwise, the measurements have no noise. Even if you set HasNoise to false, the sensor reports the measurement noise covariance matrix specified in the MeasurementNoise property of its object detection outputs.

When the sensor reports tracks, the sensor uses the measurement covariance matrix to estimate the track state and state covariance matrix.

Data Types: logical

HasFalseAlarms — Enable creating false alarm radar detections

true or 1 (default) | false or 0

Enable creating false alarm radar measurements, specified as a logical 1 (true) or 0 (false). Set this property to true to report false alarms. Otherwise, the radar reports only actual detections.

Data Types: logical

HasOcclusion — Enable occlusion from extended objects

true or 1 (default) | false or 0

Enable occlusion from extended objects, specified as a logical 1 (true) or 0 (false). Set this property to true to model occlusion from extended objects. The sensor models two types of occlusion, self occlusion and inter-object occlusion. Self occlusion occurs when one side of an extended object occludes another side. Inter-object occlusion occurs when one extended object stands in the line of sight of another extended object or a point target. Note that both extended objects and point targets can be occluded by extended objects, but a point target cannot occlude another point target or an extended object.

Data Types: logical

HasGhosts — Enable ghost targets in target reports

false or 0 (default) | true or 1

Enable ghost targets in target reports, specified as a logical 1 (true) or 0 (false). The sensor generates ghost targets for multipath propagation paths up to three reflections between transmission and reception of the radar signal. The sensor only generates ghost targets when the DetectionMode property is set to 'Monostatic'.

Data Types: logical

HasRangeAmbiguities — Enable range ambiguities

false or 0 (default) | true or 1

Enable range ambiguities, specified as a logical 0 (false) or 1 (true). Set this property to true to enable sensor range ambiguities. In this case, the sensor does not resolve range ambiguities, and target ranges beyond the MaxUnambiguousRange are wrapped into the interval [0, MaxUnambiguousRange]. When false, the sensor reports targets at their unambiguous range.

Data Types: logical

HasRangeRateAmbiguities — Enable range-rate ambiguities

false or 0 (default) | true or 1

Enable range-rate ambiguities, specified as a logical 0 (false) or 1 (true). Set this property to true to enable sensor range-rate ambiguities. When true, the sensor does not resolve range rate ambiguities. Target range rates beyond the MaxUnambiguousRadialSpeed are wrapped into the interval [0, MaxUnambiguousRadialSpeed]. When false, the sensor reports targets at their unambiguous range rates.

Dependencies

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

Data Types: logical

HasINS — Enable inertial navigation system (INS) input

false or 0 (default) | true or 1

Enable the INS input argument, which passes the current estimate of the sensor platform pose to the sensor, specified as a logical 0 (false) or 1 (true). When true, pose information is added to the MeasurementParameters structure of the reported detections or the StateParameters structure of the reported tracks, based on the TargetReportFormat property. Pose information enables tracking and fusion algorithms to estimate the state of the target in the scenario frame.

Data Types: logical

HasScanLoss — Enable losses due to electronic scanning off-broadside

false (default) | true

Enable scan loss due to electronic scanning off-broadside, specified as false or true. Scan loss models the effect of antenna array beam broadening when the radar points to an off-broadside angle.

Dependencies

To enable this property, set the ScanMode property to 'Custom'.

Data Types: logical

MaxNumReportsSource — Source of maximum for number of detection or track reports

'Auto' (default) | 'Property'

Source of the maximum for the number of detection or track reports, specified as one of these options:

• 'Auto' — The sensor reports all detections or tracks.

• 'Property' — The sensor reports the first N valid detections or tracks, where N is equal to the MaxNumReports property value.

MaxNumReports — Maximum number of detection or track reports

100 (default) | positive integer

Maximum number of detection or track reports, specified as a positive integer. The sensor reports detections, in order of increasing distance from the sensor, until reaching this maximum number.

Dependencies

To enable this property, set the MaxNumReportsSource property to 'Property'.

Data Types: double

TargetReportFormat — Format of generated target reports

'Clustered detections' (default) | 'Tracks' | 'Detections'

Format of generated target reports, specified as one of these options:

• 'Clustered detections' — The sensor generates target reports as clustered detections, where each target is reported as a single detection that is the centroid of the unclustered target detections. The sensor returns clustered detections as a cell array of objectDetection objects. To enable this option, set the DetectionMode property to 'Monostatic' and set the EmissionsInputPort property to false.

• 'Tracks' — The sensor generates target reports as tracks, which are clustered detections that have been processed by a tracking filter. The sensor returns tracks as an array of objectTrack objects. To enable this option, set the DetectionMode property to 'Monostatic' and set the EmissionsInputPort property to false.

• 'Detections' — The sensor generates target reports as unclustered detections, where each target can have multiple detections. The sensor returns unclustered detections as a cell array of objectDetection objects.

DetectionCoordinates — Coordinate system used to report detections

'Body' | 'Scenario' | 'Sensor rectangular | 'Sensor spherical'

Coordinate system used to report detections, specified as one of these options:

• 'Scenario' — Detections are reported in the rectangular scenario coordinate frame. The scenario coordinate system is defined as the local navigation frame at simulation start time. To enable this value, set the HasINS property to true.

• 'Body' — Detections are reported in the rectangular body system of the sensor platform.

• 'Sensor rectangular' — Detections are reported in the sensor rectangular body coordinate system.

• 'Sensor spherical' — Detections are reported in a spherical coordinate system derived from the sensor rectangular body coordinate system. This coordinate system is centered at the sensor and aligned with the orientation of the radar on the platform.

When the DetectionMode property is set to 'Monostatic', you can specify the DetectionCoordinates as 'Body' (default for 'Monostatic'), 'Scenario', 'Sensor rectangular', or 'Sensor spherical'. When the DetectionMode property is set to 'ESM' or 'Bistatic', the default value of the DetectionCoordinates property is 'Sensor spherical', which cannot be changed.

Example: 'Sensor spherical'

Measurement Resolution and Bias

AzimuthResolution — Azimuth resolution of radar (deg)

1 (default) | positive scalar

Azimuth resolution of the radar, in degrees, specified as a positive scalar. The azimuth resolution defines the minimum separation in azimuth angle at which the radar can distinguish between two targets. The azimuth resolution is typically the half-power beamwidth of the azimuth angle beamwidth of the radar.

Tunable: Yes

Data Types: double

ElevationResolution — Elevation resolution of radar (deg)

5 (default) | positive scalar

Elevation resolution of the radar, in degrees, specified as a positive scalar. The elevation resolution defines the minimum separation in elevation angle at which the radar can distinguish between two targets. The elevation resolution is typically the half-power beamwidth of the elevation angle beamwidth of the radar.

Tunable: Yes

Dependencies

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

Data Types: double

RangeResolution — Range resolution of radar (m)

100 (default) | positive scalar

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

Tunable: Yes

Data Types: double

RangeRateResolution — Range-rate resolution of radar (m/s)

10 (default) | positive scalar

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

Tunable: Yes

Dependencies

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

Data Types: double

AzimuthBiasFraction — Azimuth bias fraction of radar

0.1 (default) | nonnegative scalar

Azimuth bias fraction of the radar, specified as a nonnegative scalar. Azimuth bias is expressed as a fraction of the azimuth resolution specified in the AzimuthResolution property. This value sets a lower bound on the azimuthal accuracy of the radar and is dimensionless.

Data Types: double

ElevationBiasFraction — Elevation bias fraction of radar

0.1 (default) | nonnegative scalar

Elevation bias fraction of the radar, specified as a nonnegative scalar. Elevation bias is expressed as a fraction of the elevation resolution specified by the ElevationResolution property. This value sets a lower bound on the elevation accuracy of the radar and is dimensionless.

Dependencies

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

Data Types: double

RangeBiasFraction — Range bias fraction

0.05 (default) | nonnegative scalar

Range bias fraction of the radar, specified as a nonnegative scalar. Range bias is expressed as a fraction of the range resolution specified by the RangeResolution property. This property sets a lower bound on the range accuracy of the radar and is dimensionless.

Data Types: double

RangeRateBiasFraction — Range-rate bias fraction

0.05 (default) | nonnegative scalar

Range-rate bias fraction of the radar, specified as a nonnegative scalar. Range-rate bias is expressed as a fraction of the range-rate resolution specified by the RangeRateResolution property. This property sets a lower bound on the range rate accuracy of the radar and is dimensionless.

Dependencies

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

Data Types: double

Detection Settings

CenterFrequency — Center frequency of radar band (Hz)

300e6 (default) | positive scalar

Center frequency of the radar band, specified as a positive scalar. Units are in Hz.

Tunable: Yes

Data Types: double

Bandwidth — Radar waveform bandwidth

3e6 (default) | positive real scalar

Radar waveform bandwidth, specified as a positive real scalar. Units are in Hz.

Example: 100e3

Tunable: Yes

Data Types: double

WaveformTypes — Types of detectable waveforms

0 (default) | L-element vector of nonnegative integers

Types of detectable waveforms, specified as an L-element vector of nonnegative integers. Each integer represents a type of waveform detectable by the radar.

Example: [1 4 5]

Data Types: double

ConfusionMatrix — Probability of correct classification of detected waveform

1 (default) | positive scalar | L-element vector of nonnegative real values | L-by-L matrix of nonnegative real values

Probability of correct classification of a detected waveform, specified as a positive scalar, an L-element vector of nonnegative real values, or an L-by-L matrix of nonnegative real values, where L is the number of waveform types detectable by the sensor, as indicated by the value set in the WaveformTypes property. Matrix values must be in the range [0, 1].

The (i, j) matrix element represents the probability of classifying the ith waveform as the jth waveform. When you specify this property as a scalar from 0 through 1, the value is expanded along the diagonal of the confusion matrix. When specified as a vector, the vector is aligned as the diagonal of the confusion matrix. When defined as a scalar or a vector, the off-diagonal values are set to (1 – val)/(L –1), where val is the value of the diagonal element.

Data Types: double

Sensitivity — Minimum operational sensitivity of receiver

-50 (default) | scalar

Minimum operational sensitivity of receiver, specified as a scalar. Sensitivity includes isotropic antenna receiver gain. Units are in dBmi.

Example: -10

Data Types: double

DetectionThreshold — Minimum SNR required to declare detection

5 (default) | scalar

Minimum signal-to-noise ratio (SNR) required to declare a detection, specified as a scalar. Units are in dB.

Example: -1

Data Types: double

DetectionProbability — Probability of detecting reference target

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

Probability of detecting a reference target, specified as a scalar in the range (0, 1]. This property defines the probability of detecting a reference target with a radar cross-section (RCS), ReferenceRCS, at the reference detection range, ReferenceRange.

Tunable: Yes

Data Types: double

ReferenceRange — Reference range for given probability of detection (m)

100e3 (default) | positive real scalar

Reference range for the given probability of detection and the given reference radar cross-section (RCS), in meters, specified as a positive real scalar. The reference range is the range, at which a target having a radar cross-section specified by the ReferenceRCS property is detected with a probability of detection specified by the DetectionProbability property.

Tunable: Yes

Data Types: double

ReferenceRCS — Reference radar cross-section for given probability of detection (dBsm)

0 (default) | real scalar

Reference radar cross-section (RCS) for a given probability of detection and reference range, specified as a real scalar. The reference RCS is the RCS value at which a target is detected with a probability specified by DetectionProbability at the specified ReferenceRange value. Units are in decibel square meters (dBsm).

Tunable: Yes

Data Types: double

FalseAlarmRate — False alarm report rate

1e-6 (default) | positive real scalar in range [10^–7, 10^–3]

False alarm report rate within each radar resolution cell, specified as a positive real scalar in the range [10^–7, 10^–3]. Units are dimensionless. The object determines resolution cells from the AzimuthResolution and RangeResolution properties and, when enabled, from the ElevationResolution and RangeRateResolution properties.

Tunable: Yes

Data Types: double

FieldOfView — Azimuthal and elevation field of view of radar (deg)

[1 5] | 1-by-2 positive real-valued vector

Angular field of view of the radar, in degrees, specified as a 1-by-2 positive real-valued vector of the form [azfov elfov]. The field of view defines the total angular extent spanned by the sensor. The azimuth field of view, azfov, must be in the range (0, 360]. The elevation field of view, elfov, must be in the range (0, 180]. Targets outside of the angular field of view will not be detected. Units are in degrees.

Dependencies

To enable this property, set the ScanMode property to any value except 'Custom'. When the ScanMode property is set to 'Custom', the field of view is determined by the angular resolutions specified in AzimuthResolution and ElevationResolution properties and the current look angle specified in LookAngle

Data Types: double

RangeLimits — Minimum and maximum range of radar (m)

[0 100e3] (default) | 1-by-2 nonnegative real-valued vector

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

Tunable: Yes

RangeRateLimits — Minimum and maximum range rate of radar (m/s)

[-200 200] (default) | 1-by-2 real-valued vector

Minimum and maximum range rate of radar, in meters per second, specified as a 1-by-2 real-valued vector of the form [min, max]. The radar does not detect targets that are outside this range rate. The maximum range rate, max, must be greater than the minimum range rate, min.

Tunable: Yes

Dependencies

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

MaxUnambiguousRange — Maximum unambiguous detection range

100e3 (default) | positive scalar

Maximum unambiguous detection range, specified as a positive scalar. Maximum unambiguous range defines the maximum range for which the radar can unambiguously resolve the range of a target. When HasRangeAmbiguities is set to true, targets detected at ranges beyond the maximum unambiguous range are wrapped into the range interval [0, MaxUnambiguousRange]. Units are in meters.

This property also applies to false target detections when you set the HasFalseAlarms property to true. In this case, the property defines the maximum range at which false alarms can be generated.

Example: 5e3

Tunable: Yes

Dependencies

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

Data Types: double

MaxUnambiguousRadialSpeed — Maximum unambiguous radial speed

200 (default) | positive scalar

Maximum unambiguous radial speed, specified as a positive scalar. Radial speed is the magnitude of the target range rate. Maximum unambiguous radial speed defines the radial speed for which the radar can unambiguously resolve the range rate of a target. When HasRangeRateAmbiguities is set to true, targets detected at range rates beyond the maximum unambiguous radial speed are wrapped into the range rate interval [–MaxUnambiguousRadialSpeed, MaxUnambiguousRadialSpeed]. Units are in meters per second.

This property also applies to false target detections obtained when you set both the HasRangeRate and HasFalseAlarms properties to true. In this case, the property defines the maximum radial speed at which false alarms can be generated.

Tunable: Yes

Dependencies

To enable this property, set HasRangeRate and HasRangeRateAmbiguities to true.

Data Types: double

RadarLoopGain — Radar loop gain

real scalar

This property is read-only.

Radar loop gain, specified as a real scalar. RadarLoopGain depends on the values of the DetectionProbability, ReferenceRange, ReferenceRCS, and FalseAlarmRate properties. Radar loop gain is a function of the reported signal-to-noise ratio of the radar, SNR, the target radar cross-section, RCS, and the target range, R, as described by this equation:

SNR = RadarLoopGain + RCS – 40log₁₀(R)

SNR and RCS are in decibels and decibel square meters, respectively, R is in meters, and RadarLoopGain is in decibels.

Data Types: double

Interference and Emission Inputs

InterferenceInputPort — Enable interference input

false or 0 (default) | true or 1

Enable interference input, specified as a logical 0 (false) or 1 (true). Set this property to true to enable interference input when running the radar.

Dependencies

To enable this property, set DetectionMode to 'Monostatic' and set EmissionsInputPort to false.

Data Types: logical

EmissionsInputPort — Enable emissions input

false or 0 (default) | true or 1

Enable emissions input, specified as a logical 0 (false) or 1 (true). Set this property to true to enable emissions input when running the radar.

Dependencies

To enable this property, set DetectionMode to 'Monostatic' and set InterferenceInputPort to false.

Data Types: logical

EmitterIndex — Unique identifier of monostatic emitter

1 (default) | positive integer

Unique identifier of the monostatic emitter, specified as a positive integer. Use this index to identify the monostatic emitter providing the reference emission for the radar.

Dependencies

To enable this property, set DetectionMode to 'Monostatic' and set EmissionsInputPort to true.

Data Types: double

Tracking Settings

FilterInitializationFcn — Kalman filter initialization function

@initcvekf (default) | function handle | character vector | string scalar

Kalman filter initialization function, specified as a function handle or as a character vector or string scalar of the name of a valid Kalman filter initialization function.

The table shows the initialization functions that you can use to specify FilterInitializationFcn.

Initialization Function	Function Definition
initcaabf	Initialize constant-acceleration alpha-beta Kalman filter
initcvabf	Initialize constant-velocity alpha-beta Kalman filter
initcakf	Initialize constant-acceleration linear Kalman filter.
initcvkf	Initialize constant-velocity linear Kalman filter.
initcaekf	Initialize constant-acceleration extended Kalman filter.
initctekf	Initialize constant-turnrate extended Kalman filter.
initcvekf	Initialize constant-velocity extended Kalman filter.
initcaukf	Initialize constant-acceleration unscented Kalman filter.
initctukf	Initialize constant-turnrate unscented Kalman filter.
initcvukf	Initialize constant-velocity unscented Kalman filter.

You can also write your own initialization function. The function must have the following syntax:

filter = filterInitializationFcn(detection)

The input to this function is a detection report like those created by an objectDetection object. The output of this function must be a tracking filter object, such as trackingKF, trackingEKF, trackingUKF, or trackingABF.

To guide you in writing this function, you can examine the details of the supplied functions from within MATLAB^®. For example:

type initcvekf

Dependencies

To enable this property, set the TargetReportFormat property to 'Tracks'.

Data Types: function_handle | char | string

ConfirmationThreshold — Threshold for track confirmation

[2 3] (default) | 1-by-2 vector of positive integers

Threshold for track confirmation, specified as a 1-by-2 vector of positive integers of the form [M N]. A track is confirmed if it receives at least M detections in the last N updates. M must be less than or equal to N.

• When setting M, take into account the probability of object detection for the sensors. The probability of detection depends on factors such as occlusion or clutter. You can reduce M when tracks fail to be confirmed or increase M when too many false detections are assigned to tracks.

• When setting N, consider the number of times you want the tracker to update before it makes a confirmation decision. For example, if a tracker updates every 0.05 seconds, and you want to allow 0.5 seconds to make a confirmation decision, set N = 10.

Example: [3 5]

Dependencies

To enable this property, set the TargetReportFormat property to 'Tracks'.

Data Types: double

DeletionThreshold — Threshold for track deletion

[5 5] (default) | 1-by-2 vector of positive integers

Threshold for track deletion, specified as a 1-by-2 vector of positive integers of the form [P R]. If a confirmed track is not assigned to any detection P times in the last R tracker updates, then the track is deleted. P must be less than or equal to R.

• To reduce how long the radar maintains tracks, decrease R or increase P.

• To maintain tracks for a longer time, increase R or decrease P.

Example: [3 5]

Dependencies

To enable this property, set the TargetReportFormat property to 'Tracks'.

Data Types: double

TrackCoordinates — Coordinate system of reported tracks

'Scenario' | 'Body' | 'Sensor'

Coordinate system used to report tracks, specified as one of these options:

• 'Scenario' — Tracks are reported in the rectangular scenario coordinate frame. The scenario coordinate system is defined as the local navigation frame at simulation start time. To enable this option, set the HasINS property to true.

• 'Body' — Tracks are reported in the rectangular body system of the sensor platform.

• 'Sensor' — Tracks are reported in the sensor rectangular body coordinate system.

Dependencies

To enable this property, set the TargetReportFormat property to 'Tracks'.

Target Profiles

Profiles — Physical characteristics of target platforms

structure | array of structures

Physical characteristics of target platforms, specified as a structure or an array of structures. Unspecified fields take default values.

• If you specify the property as a structure, then the structure applies to all target platforms.

• If you specify the property as an array of structures, then each structure in the array applies to the corresponding target platform based on the PlatformID filed. In this case, you must specify each PlatformID filed as a positive integer and must not leave the field as empty.

Field	Description	Default Value
PlatformID	Scenario-defined platform identifier, defined as a positive integer.	empty
ClassID	User-defined platform classification identifier, defined as a nonnegative integer.	0
Dimensions	Platform dimensions, defined as a structure with these fields: Length Width Height OriginOffset	0
Signatures	Platform signatures, defined as a cell array containing an rcsSignature object, which specifies the RCS signature of the platform.	The default rcsSignature object

See Platform (Sensor Fusion and Tracking Toolbox) for more details on these fields.

Data Types: struct

Usage

Syntax

reports = rdr(targetPoses,simTime)

reports = rdr(targetPoses,interferences,simTime)

reports = rdr(emissions,emitterConfigs,simTime)

reports = rdr(emissions,simTime)

reports = rdr(___,insPose,simTime)

[reports,numReports,config] = rdr(___)

Description

Monostatic Detection Mode

These syntaxes apply when you set the DetectionMode property to 'Monostatic'.

reports = rdr(targetPoses,simTime) returns monostatic target reports from the target poses, targetPoses, at the current simulation time, simTime. The object can generate reports for multiple targets. To enable this syntax:

• Set the DetectionMode property to 'Monostatic'.

• Set the InterferenceInputPort property to false.

• Set the EmissionsInputPort property to false.

reports = rdr(targetPoses,interferences,simTime) specifies the interference signals, interferences, in the radar signal transmission. To enable this syntax:

• Set the DetectionMode property to 'Monostatic'.

• Set the InterferenceInputPort property to true.

• Set the EmissionsInputPort property to false.

reports = rdr(emissions,emitterConfigs,simTime) returns monostatic target reports based on the emission signal, emissions, and the configurations of the corresponding emitters, emitterConfigs, that generate the emissions. To enable this syntax:

• Set the DetectionMode property to 'Monostatic'.

• Set the InterferenceInputPort property to false.

• Set the EmissionsInputPort property to true.

Bistatic or ESM Detection Mode

This syntax applies when you set the DetectionMode property to 'Bistatic' or 'ESM'. In these two modes, the TargetReportFormat can only be 'Detections' and the DetectionCoordinates can only be 'Sensor spherical'.

reports = rdr(emissions,simTime) returns Bistatic or ESM reports form the radar signal emissions at the simulation time, simTime.

Provide INS Input

This syntax applies when you set the HasINS property to true.

reports = rdr(___,insPose,simTime) specifies the pose information of the radar platform through an INS estimate. The insPose argument is the second to the last argument before the simTime argument. This syntax can be used with any of the previous syntaxes. See the HasINS property for more details.

Output Additional Information

Use this syntax if you want to output additional information of the reports.

[reports,numReports,config] = rdr(___) returns the number of reports, numReports, and the configuration of the radar, config, at the current simulation time.

Input Arguments

targetPoses — Target poses

array of structures

Radar scenario target poses, specified as an array of structures. Each structure corresponds to a target. You can generate the structure using the targetPoses object function of a platform. You can also create such a structure manually. This table shows the fields of the structure:

Field	Description
PlatformID	Unique identifier for the platform, specified as a positive integer. This is a required field with no default value.
ClassID	User-defined integer used to classify the type of target, specified as a nonnegative integer. 0 is reserved for unclassified platform types and is the default value.
Position	Position of the target in platform coordinates, specified as a real-valued, 1-by-3 vector. This is a required field with no default value. Units are in meters.
Velocity	Velocity of the target in platform coordinates, specified as a real-valued, 1-by-3 vector. Units are in meters per second. The default is [0 0 0].
Acceleration	Acceleration of the target in platform coordinates specified as a 1-by-3 row vector. Units are in meters per second-squared. The default is [0 0 0].
Orientation	Orientation of the target with respect to platform coordinates, specified as a scalar quaternion or a 3-by-3 rotation matrix. Orientation defines the frame rotation from the platform coordinate system to the current target body coordinate system. Units are dimensionless. The default is quaternion(1,0,0,0).
AngularVelocity	Angular velocity of the target in platform coordinates, specified as a real-valued, 1-by-3 vector. The magnitude of the vector defines the angular speed. The direction defines the axis of clockwise rotation. Units are in degrees per second. The default is [0 0 0].

The values of the Position, Velocity, and Orientation fields are defined with respect to the platform body frame.

If the dimensions of the target or RCS signature change with respect to time, you can specify these two additional fields in the structure:

Field	Description
Dimensions	Platform dimensions, specified as a structure with these fields: Length Width Height OriginOffset
Signatures	Platform signatures, specified as a cell array containing an rcsSignature object, which specifies the RCS signature of the platform.

If the dimensions of the target and RCS signature remain static with respect to time, you can specify its dimensions and RCS signature using the Profiles property.

interferences — Interference radar emissions

array of radarEmission objects | cell array of radarEmission objects | array of structure

Interference radar emissions, specified as an array or cell array of radarEmission objects. You can also specify interferences as an array of structures with field names corresponding to the property names of the radarEmission object.

emissions — Radar emissions

array of radarEmission objects | cell array of radarEmission objects | array of structures

Radar emissions, specified as an array or cell array of radarEmission objects. You can also specify emissions as an array of structures with field names corresponding to the property names of the radarEmission object.

emitterConfigs — Emitter configurations

array of structures

Emitter configurations, specified as an array of structures. This array must contain the configuration of the radar emitter whose EmitterIndex matches the value of the EmitterIndex property of the radarDataGenerator. Each structure has these fields:

Field	Description
EmitterIndex	Unique emitter index.
IsValidTime	Valid emission time, returned as 0 or 1. The value of IsValidTime is 0 when emitter updates are requested at times that are between update intervals specified by UpdateInterval.
IsScanDone	IsScanDone is true when the emitter has completed a scan.
FieldOfView	Field of view of the emitter.
MeasurementParameters	MeasurementParameters is an array of structures containing the coordinate frame transforms needed to transform positions and velocities in the top-level frame to the current emitter frame.

For more details on MeasurementParameters, see Measurement Parameters.

Data Types: struct

insPose — Platform pose from INS

structure

Platform pose information from an inertial navigation system (INS), specified as a structure with these fields:

Field	Definition
Position	Position in the scenario frame, specified as a real-valued 1-by-3 vector. Units are in meters.
Velocity	Velocity in the scenario frame, specified as a real-valued 1-by-3 vector. Units are in meters per second.
Orientation	Orientation with respect to the scenario frame, specified as a quaternion or a 3-by-3 real-valued rotation matrix. The rotation is from the navigation frame to the current INS body frame. This is also referred to as a "parent to child" rotation.

simTime — Current simulation time

nonnegative scalar

Current simulation time, specified as a nonnegative scalar. The radarScenario object calls the scan radar sensor at regular time intervals. The sensor only generates reports at simulation times corresponding to integer multiples of the update interval, which is given by the reciprocal of the UpdateRate property.

• When called at these intervals, targets are reported in reports, the number of reports is returned in numReports, and the IsValidTime field of the returned config structure is returned as true.

• When called at all other simulation times, the sensor returns an empty report, numReports is returned as 0, and the IsValidTime field of the returned config structure is returned as false.

Example: 10.5

Data Types: double

Output Arguments

reports — Detections or track reports

cell array of objectDetection objects | cell array of objectTrack objects

Detection or track reports, returned as one of these options:

• A cell array of objectDetection objects, when the TargetReportFormat property is set to 'Detections' or 'Clustered detections'. Additionally, when the DetectionMode is set to 'ESM' or 'Bistatic', the sensor can only generate unclustered detections and cannot generate clustered detections.

• A cell array of objectTrack objects, when the TargetReportFormat property is set to 'Tracks'. The sensor can only output tracks when the DetectionMode is set to 'Monostatic'. The sensor returns only confirmed tracks, which are tracks that satisfy the confirmation threshold specified in the ConfirmationThreshold property. For these tracks, the IsConfirmed property of the object is true.

In generated code, reports return as equivalent structures with field names corresponding to the property names of the objectDetection object or the property names of the objectTrack objects, based on the TargetReportFormat property.

The format and coordinates of the measurement states or track states is determined by the specifications of the HasRangeRate, HasElevation, HasINS, TaregetReportFormat, and DetectionCoordinates properties. For more details, see Detection and Track State Coordinates.

numReports — Number of reported detections or tracks

nonnegative integer

Number of reported detections or tracks, returned as a nonnegative integer. numReports is equal to the length of the reports argument.

Data Types: double

config — Current sensor configuration

structure

Current sensor configuration, specified as a structure. This output can be used to determine which objects fall within the radar beam during object execution.

Field	Description
SensorIndex	Unique sensor index, returned as a positive integer.
IsValidTime	Valid detection time, returned as true or false. IsValidTime is false when detection updates are requested between update intervals specified by the update rate.
IsScanDone	IsScanDone is true when the sensor has completed a scan.
FieldOfView	Field of view of the sensor, returned as a 2-by-1 vector of positive real values, [azfov;elfov]. azfov and elfov represent the field of view in azimuth and elevation, respectively.
RangeLimits	Minimum and maximum range of sensor, in meters, specified as a 1-by-2 nonnegative real-valued vector of the form [rmin,rmax].
RangeRateLimits	Minimum and maximum range rate of sensor, in meters per second, specified as a 1-by-2 real-valued vector of the form [rrmin,rrmax].
MeasurementParameters	Sensor measurement parameters, returned as an array of structures containing the coordinate frame transforms needed to transform positions and velocities in the top-level frame to the current sensor frame.

Data Types: struct

Object Functions

To use an object function, specify the System object™ as the first input argument. For example, to release system resources of a System object named obj, use this syntax:

release(obj)

Specific to radarDataGenerator

coverageConfig	Sensor and emitter coverage configuration
radarTransceiver	Create corresponding radar transceiver from radarDataGenerator
perturb	Apply perturbations to object
perturbations	Perturbation defined on object

Common to All System Objects

step	Run System object algorithm
release	Release resources and allow changes to System object property values and input characteristics
reset	Reset internal states of System object

Examples

Model Air Traffic Control Tower Scanning

Create three targets by specifying their platform ID, position, and velocity.

tgt1 = struct('PlatformID',1, ...
    'Position',[0 -50e3 -1e3], ...
    'Velocity',[0 900*1e3/3600 0]);

tgt2 = struct('PlatformID',2, ...
    'Position',[20e3 0 -500], ...
    'Velocity',[700*1e3/3600 0 0]);

tgt3 = struct('PlatformID',3, ...
    'Position',[-20e3 0 -500], ...
    'Velocity',[300*1e3/3600 0 0]);

Create an airport surveillance radar that is 15 meters above the ground.

rpm = 12.5;
fov = [1.4; 5]; % [azimuth; elevation]
scanrate = rpm*360/60;  % deg/s
updaterate = scanrate/fov(1); % Hz

sensor = radarDataGenerator(1,'Rotator', ...
    'UpdateRate',updaterate, ...
    'MountingLocation',[0 0 -15], ...
    'MaxAzimuthScanRate',scanrate, ...
    'FieldOfView',fov, ...
    'AzimuthResolution',fov(1));

Generate detections from a full scan of the radar.

simTime = 0;
detBuffer = {};
while true
    [dets,numDets,config] = sensor([tgt1 tgt2 tgt3],simTime);
    detBuffer = [detBuffer; dets]; %#ok<AGROW>

    % Is full scan complete?
    if config.IsScanDone
        break % yes
    end
    simTime = simTime + 1/sensor.UpdateRate;
end

radarPosition = [0 0 0];
tgtPositions = [tgt1.Position; tgt2.Position; tgt3.Position];

Visualize the results.

clrs = lines(3);

figure
hold on

% Plot radar position
plot3(radarPosition(1),radarPosition(2),radarPosition(3),'Marker','s', ...
    'DisplayName','Radar','MarkerFaceColor',clrs(1,:),'LineStyle','none')

% Plot truth
plot3(tgtPositions(:,1),tgtPositions(:,2),tgtPositions(:,3),'Marker','^', ...
    'DisplayName','Truth','MarkerFaceColor',clrs(2,:),'LineStyle', 'none')

% Plot detections
if ~isempty(detBuffer)
    detPos = cellfun(@(d)d.Measurement(1:3),detBuffer, ...
        'UniformOutput',false);
    detPos = cell2mat(detPos')';
    plot3(detPos(:,1),detPos(:,2),detPos(:,3),'Marker','o', ...
        'DisplayName','Detections','MarkerFaceColor',clrs(3,:),'LineStyle','none')
end

xlabel('X(m)')
ylabel('Y(m)')
axis('equal')
legend('Location','east')

Detect Radar Emission with radarDataGenerator

Create a radar emission and then detect the emission using a radarDataGenerator object.

First, create a radar emission.

orient = quaternion([180 0 0],'eulerd','zyx','frame');
rfSig = radarEmission('PlatformID',1,'EmitterIndex',1,'EIRP',100, ...
    'OriginPosition',[30 0 0],'Orientation',orient);

Then, create an ESM sensor using radarDataGenerator.

sensor = radarDataGenerator(1,'DetectionMode','ESM');

Detect the RF emission.

time = 0;
[dets,numDets,config] = sensor(rfSig,time)

dets = 1x1 cell array
    {1x1 objectDetection}

numDets = 
1

config = struct with fields:
              SensorIndex: 1
              IsValidTime: 1
               IsScanDone: 0
              FieldOfView: [1 5]
              RangeLimits: [0 Inf]
          RangeRateLimits: [0 Inf]
    MeasurementParameters: [1x1 struct]

Point Radar at Target

Create a radar that can be pointed directly at targets of interest to generate statistical detections. This setup is useful in cases where the azimuth and elevation of the target are already estimated by a tracker. Thus the radar can be cued to detect the target to update the track in between surveillance updates and other target track updates. To specify such a radar, set the ScanMode property of radarDataGenerator to "Custom".

rdr = radarDataGenerator(1,'ScanMode','Custom','HasElevation',true)

rdr = 
  radarDataGenerator with properties:

              SensorIndex: 1
               UpdateRate: 1
            DetectionMode: 'Monostatic'
                 ScanMode: 'Custom'
    InterferenceInputPort: 0

         MountingLocation: [0 0 0]
           MountingAngles: [0 0 0]

     EffectiveFieldOfView: [2 10]
                LookAngle: [0 0]
              RangeLimits: [0 100000]

     DetectionProbability: 0.9000
           FalseAlarmRate: 1.0000e-06
           ReferenceRange: 100000

       TargetReportFormat: 'Clustered detections'

  Use get to show all properties

Create a target at which to point the radar. The target is located at a range of 1 km from the radar at an azimuth of 10 degrees and an elevation of 5 degrees.

tgtRg = 1e3;
tgtAz = 10;
tgtEl = 5;

[X,Y,Z] = sph2cart(deg2rad(tgtAz),deg2rad(tgtEl),tgtRg);

tgt = struct(PlatformID=1,Position=[X Y Z]);

Point the radar directly at the target. Generate the statistical detection.

rdr.LookAngle = [tgtAz tgtEl];

simTime = 0;
dets = rdr(tgt,simTime);

Compare the measured target location to the actual position.

detpos = dets{1}.Measurement;

ttb = table(detpos,tgt.Position', ...
    RowNames=["X" "Y" "Z"],VariableNames=["Measured" "Actual"])

ttb=3×2 table
         Measured    Actual
         ________    ______

    X     986.54     981.06
    Y     177.22     172.99
    Z     67.795     87.156

Create a theaterPlot object. Plot the radar, the target, and the radar detections. Overlay a plot of the radar coverage.

tp = theaterPlot(AxesUnits=["m" "m" "m"],XLimits=[0 2e3]);

pltPlotter = platformPlotter(tp,DisplayName="Radar Platform");
tgtPlotter = platformPlotter(tp,DisplayName="Targets", ...
    MarkerFaceColor="#D95319");

plotPlatform(pltPlotter,[0 0 0])
plotPlatform(tgtPlotter,tgt.Position)

covPlotter = coveragePlotter(tp,DisplayName="Radar Coverage");
covcfg = coverageConfig(rdr);
plotCoverage(covPlotter,covcfg)

detPlotter = detectionPlotter(tp,DisplayName="Radar Detections");
plotDetection(detPlotter,detpos')

axis equal

Algorithms

Convenience Syntaxes

The convenience syntaxes set several properties together to model a specific type of radar.

No Scanning

Sets ScanMode to 'No scanning'.

Raster Scanning

This syntax sets these properties:

Property	Value
ScanMode	'Mechanical'
HasElevation	true
MaxMechanicalScanRate	[75; 75]
MechanicalAzimuthLimits	[-45 45]
MechanicalElevationLimits	[-10 0]
ElectronicAzimuthLimits	[-45 45]
ElectronicElevationLimits	[-10 0]

Change the ScanMode property to 'Electronic' to perform an electronic raster scan over the same volume as a mechanical scan.

Rotator Scanning

This syntax sets these properties:

Property	Value
ScanMode	'Mechanical'
FieldOfView	[1; 10]
HasElevation	false or true
MechanicalAzimuthLimits	[0 360]
MechanicalElevationLimits	[-10 0]
ElevationResolution	10/sqrt(12)

Sector Scanning

This syntax sets these properties:

Property	Value
ScanMode	'Mechanical'
FieldOfView	[1; 10]
HasElevation	false
MechanicalAzimuthLimits	[-45 45]
MechanicalElevationLimits	[-10 0]
ElectronicAzimuthLimits	[-45 45]
ElectronicElevationLimits	[-10 0]
ElevationResolution	10/sqrt(12)

Changing the ScanMode property to 'Electronic' lets you perform an electronic raster scan over the same volume as a mechanical scan.

Custom Scanning

The LookAngle property is not read-only only for this mode. and enables the BeamShape property.

This syntax also disables these properties:

MaxAzimuthScanRate	MaxElevationScanRate	MechanicalAzimuthLimits
MechanicalElevationLimits	ElectronicAzimuthLimits	ElectronicElevationLimits
MechanicalAngle	ElectronicAngle	FieldOfView
EmissionsInputPort

In this syntax, these properties are now tunable:

CenterFrequency	Bandwidth	DetectionProbability
ReferenceRange	ReferenceRCS	FalseAlarmRate
RangeLimits	RangeRateLimits	MaxUnambiguousRange
MaxUnambiguousRadialSpeed	AzimuthResolution	ElevationResolution
ElevationResolution	RangeRateResolution

Radar Sensor Detection Modes

The radarDataGenerator System object can model three detection modes: monostatic, bistatic, and electronic support measures (ESM) as shown in the following figures.

For the monostatic detection mode, the transmitter and the receiver are collocated, as shown in figure (a). In this mode, the range measurement R can be expressed as R = R_T = R_R, where R_T and R_R are the ranges from the transmitter to the target and from the target to the receiver, respectively. In the radar sensor, the range measurement is R = ct/2, where c is the speed of light and t is the total time of the signal transmission. Other than the range measurement, a monostatic sensor can optionally report range-rate, azimuth, and elevation measurements of the target.

For the bistatic detection mode, the transmitter and the receiver are separated by a distance L. As shown in figure (b), the signal is emitted from the transmitter, reflected from the target, and received by the receiver. The bistatic range measurement R_b is defined as R_b = R_T + R_R − L. In the radar sensor, the bistatic range measurement is obtained by R_b = cΔt, where Δt is the time difference between the receiver receiving the direct signal from the transmitter and receiving the reflected signal from the target. Other than the bistatic range measurement, a bistatic sensor can also optionally report the bistatic range-rate, azimuth, and elevation measurements of the target. Since the bistatic range and the two bearing angles (azimuth and elevation) do not correspond to the same position vector, they cannot be combined into a position vector and reported in a Cartesian coordinate system. As a result, the measurements of a bistatic sensor can only be reported in a spherical coordinate system.

For the ESM detection mode, the receiver can only receive a signal reflected from the target or directly emitted from the transmitter, as shown in figure (c). Therefore, the only available measurements are the azimuth and elevation of the target or transmitter. These measurements can only be reported in a spherical coordinate system.

Detection and Track State Coordinates

The format of the measurement states or track states is determined by the specifications of the HasRangeRate, HasElevation, HasINS, TaregetReportFormat, and DetectionCoordinates properties.

There are two general types of detection or track coordinates:

• Cartesian coordinates — Enabled by specifying the DetectionCoordinates property as 'Body', 'Scenario', or 'Sensor rectangular'. The complete form of a Cartesian state is [x; y; z; vx; vy; vz], where x, y, and z are the Cartesian positions and vx, vy, and vz are the corresponding velocities. You can only set DetectionCoordinates as 'Scenario' when the HasINS property is set to true, so that the sensor can transform sensor detections or tracks to the scenario frame.

• Spherical coordinates — Enabled by specifying the DetectionCoordinates property as 'Sensor spherical'. The complete form of a spherical state is [az; el; rng; rr], where az, el, rng, and rr represent azimuth angle, elevation angle, range, and range rate, respectively. When the DetectionMode property of the sensor is set to 'ESM' or 'Bistatic', the sensor can only report detections in the 'Sensor spherical' frame.

When the HasRangeRate property is set to false, vx, vy, and vz are removed from the Cartesian state coordinates and rr is removed from the spherical coordinates.

When the HasElevation property is set to false, z and vz are removed from the Cartesian state coordinates and el is removed from the spherical coordinates.

When the DetectionMode property is set to 'ESM', the sensor can only report detections in the 'Sensor spherical' frame as [az; el].

When the DetectionMode property is set to 'Bistatic', the sensor can only report detections in the 'Sensor spherical' frame as [az; el; rng; rr]. Here, rng and rr are the bistatic range and range rate, respectively.

Measurement Parameters

The MeasurementParameters property of an output detection consists of an array of structures that describes a sequence of coordinate transformations from a child frame to a parent frame, or the inverse transformations. In most cases, the longest required sequence of transformations is Sensor → Platform → Scenario.

If the detections are reported in sensor spherical coordinates and HasINS is set to false, then the sequence consists only of one transformation from sensor to platform. In this transformation, the OriginPosition is same as the MountingLocation property of the sensor. The Orientation consists of two consecutive rotations. The first rotation, corresponding to the MountingAngles property of the sensor, accounts for the rotation from the platform frame (P) to the sensor mounting frame (M). The second rotation, corresponding to the azimuth and elevation angles of the sensor, accounts for the rotation from the sensor mounting frame (M) to the sensor scanning frame (S). In the S frame, the x-direction is the boresight direction, and the y-direction lies within the x-y plane of the sensor mounting frame (M).

If HasINS is true, the sequence of transformations consists of two transformations: first from the scenario frame to the platform frame, and then from the platform frame to the sensor scanning frame. In the first transformation, the Orientation is the rotation from the scenario frame to the platform frame, and the OriginPosition is the position of the platform frame origin relative to the scenario frame.

If the detections are reported in platform rectangular coordinates and HasINS is set to false, the transformation consists only of the identity.

The table shows the fields of the MeasurementParameters structure. Not all fields have to be present in the structure. The specific set of fields and their default values can depend on the type of sensor.

Field	Description
Frame	Enumerated type indicating the frame used to report measurements. When detections are reported using a rectangular coordinate system, Frame is set to 'rectangular'. When detections are reported in spherical coordinates, Frame is set 'spherical' for the first structure.
OriginPosition	Position offset of the origin of the child frame relative to the parent frame, represented as a 3-by-1 vector.
OriginVelocity	Velocity offset of the origin of the child frame relative to the parent frame, represented as a 3-by-1 vector.
Orientation	3-by-3 real-valued orthonormal frame rotation matrix. The direction of the rotation depends on the IsParentTochild field.
IsParentToChild	A logical scalar indicating if Orientation performs a frame rotation from the parent coordinate frame to the child coordinate frame. If false, Orientation instead performs a frame rotation from the child coordinate frame to the parent coordinate frame.
HasElevation	A logical scalar indicating if elevation is included in the measurement. For measurements reported in a rectangular frame, if HasElevation is false, the measurements are reported assuming 0 degrees of elevation.
HasAzimuth	A logical scalar indicating if azimuth is included in the measurement.
HasRange	A logical scalar indicating if range is included in the measurement.
HasVelocity	A logical scalar indicating if the reported detections include velocity measurements. For measurements reported in a rectangular frame, if HasVelocity is false, the measurements are reported as [x y z]. If HasVelocity is true, measurements are reported as [x y z vx vy vz].

Radar Loop Gain

The radar equation relates the signal-to-noise ratio of a received signal to the transmitted radar power, target distance and target radar cross-section and other radar parameters.

$$\frac{S}{N}=\frac{P_t{G}_t{G}_r{\lambda }^2\sigma }{{(4\pi )}^3{k}_b{T}_{0}B{N}_F{R}^{4}L}$$

where

• S/N: signal-to-noise ratio (dimensionless)

• P_t: peak transmitted power (W)

• G_t: transmit antenna gain (dimensionless)

• G_r: receive antenna gain (dimensionless)

• λ: radar wavelength (m)

• σ: radar target cross-section (m²)

• k_b: Boltzmann's constant (W/Hz/K)

• T₀: system noise temperature (K)

• B: receiver bandwidth (Hz)

• N_F: noise figure (dimensionless)

• L: general loss factor that combines losses along the transmitter-target-receiver path (dimensionless)

Separating out the signal-to-noise ratio dependence on range and radar cross-section from the other parameters yields

$$\frac{S}{N}=C^{\prime }\frac{\sigma }{R^4}$$

where all the other parameters are lumped together into C'.

When expressed in dB, the radar equation is

$$SNR=C+RCS-40\log R$$

where the constant C = 10 logC' is the radar loop gain stored in the RadarLoopGain property. C can be thought of as a constant combining all the terms of the radar design. Radar loop gain is a measure of the sensitivity of the radar. With C, you can determine the expected SNR of a received target signal at distance R with radar cross-section RCS.

The detectability factor is the minimum SNR required to declare a detection with a specified probability of detection (Pd) in the DetectionProbability and specified probability false alarm (Pfa) in the FalseAlarmRate property. The minimum radar loop gain can be derived from the receiver operating characteristic (ROC) curve of a radar. Using the ROC curves you can find the SNR as a function of Pd and Pfa. The radar loop gain is the minimum SNR. The ROC curves depend on the number of pulses and the Swerling target model.

References

[1] Doerry, Armin W. "Earth Curvature and Atmospheric Refraction Effects on Radar Signal Propagation." Sandia Report SAND2012-10690, Sandia National Laboratories, Albuquerque, NM, January 2013. https://prod.sandia.gov/techlib-noauth/access-control.cgi/2012/1210690.pdf.

[2] Doerry, Armin W. "Motion Measurement for Synthetic Aperture Radar." Sandia Report SAND2015-20818, Sandia National Laboratories, Albuquerque, NM, January 2015. https://pdfs.semanticscholar.org/f8f8/cd6de8042a7a948d611bcfe3b79c48aa9dfa.pdf.

Version History

Introduced in R2021a