sonarSensor
Generate detections from sonar emissions
Description
The sonarSensor
System object™ creates a statistical model for generating detections from sonar
emissions. You can generate detections from active or passive sonar systems. You can use
the sonarSensor
object in a scenario that models moving and stationary
platforms using trackingScenario
. The sonar sensor can simulate real detections with added
random noise and also generate false alarm detections. In addition, you can use this
object to create input to trackers such as trackerGNN
or trackerTOMHT
.
This object enables you to configure an electronically scanning sonar. A scanning
sonar changes the look angle between updates by stepping the electronic position of the
beam in increments of the angular span specified in the FieldOfView
property. The sonar scans the total region in azimuth and elevation defined by the sonar
electronic scan limits, ElectronicScanLimits
. If the scanning
limits for azimuth or elevation are set to [0 0]
, no scanning is
performed along that dimension for that scan mode.
To generate sonar detections:
Create the
sonarSensor
object and set its properties.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
Description
creates a sonar detection generator object with default property
values.sensor
= sonarSensor(SensorIndex
)
is a convenience syntax that creates a sensor
= sonarSensor(SensorIndex
,'No scanning')sonarSensor
that
stares along the sonar transducer boresight direction. No electronic
scanning is performed. This syntax sets the ScanMode
property to 'No scanning'
.
is a convenience syntax that creates a sensor
= sonarSensor(SensorIndex
,'Raster')sonarSensor
object
that electronically scans a raster pattern. The raster span is 90° in
azimuth from –45° to +45° and in elevation from the horizon to 10° above the
horizon. See Convenience Syntaxes for
the properties set by this syntax.
is a convenience syntax to create a sensor
= sonarSensor(SensorIndex
,'Sector')sonarSensor
object that
electronically scans a 90° azimuth sector from –45° to +45°. Setting
HasElevation
to true
, points the
sonar transducer towards the center of the elevation field of view. Beams
are stacked electronically to process the entire elevation spanned by the
scan limits in a single dwell. See Convenience Syntaxes for
the properties set by this syntax.
sets properties using one or more name-value pairs after all other input
arguments. Enclose each property name in quotes. For example,
sensor
= sonarSensor(___,Name,Value
)sonarSensor('DetectionCoordinates','Sensor
cartesian','MaxRange',200)
creates a sonar detection generator
that reports detections in the sensor Cartesian coordinate system and has a
maximum detection range of 200 meters. If you specify the sensor index using
the SensorIndex
property, you can omit the
SensorIndex
input.
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.
SensorIndex
— Unique sensor identifier
positive integer
Unique sensor identifier, specified as a positive integer. This property
distinguishes detections that come from different sensors in a multi-sensor
system. When creating a sonarSensor
system object, you must
either specify the SensorIndex
as the first input
argument in the creation syntax, or specify it the value for the
SensorIndex
property in the creation syntax.
Example: 2
Data Types: double
UpdateRate
— Sensor update rate
1
(default) | positive scalar
Sensor update rate, specified as a positive scalar. This interval must be
an integer multiple of the simulation time interval defined by trackingScenario
. The trackingScenario
object
calls the sonar sensor at simulation time intervals. The sonar generates new
detections at intervals defined by the reciprocal of the
UpdateRate
property. Any update requested to the
sensor between update intervals contains no detections. Units are in
hertz.
Example: 5
Data Types: double
DetectionMode
— Detection mode
'passive'
(default) |
'monostatic'
Detection mode, specified as 'passive'
or
'monostatic'
. When set to
'passive'
, the sensor operates passively. When set to
'monostatic'
, the sensor generates detections from
reflected signals originating from a collocated sonar emitter.
Example: 'Monostatic'
Data Types: char
| string
EmitterIndex
— Unique monostatic emitter index
positive integer
Unique monostatic emitter index, specified as a positive integer. The emitter index identifies the monostatic sonar emitter providing the reference signal to the sensor.
Example: 404
Dependencies
Set this property when the DetectionMode
property
is set to 'monostatic'
.
Data Types: double
MountingLocation
— Sensor location on platform
[0 0 0]
(default) | 1-by-3 real-valued vector
Sensor location on platform, specified as a 1-by-3 real-valued vector. This property defines the coordinates of the sensor with respect to the platform origin. The default value specifies that the sensor origin is at the origin of its platform. Units are in meters.
Example: [.2 0.1 0]
Data Types: double
MountingAngles
— Orientation of sensor
[0 0 0]
(default) | 3-element real-valued vector
Orientation of the sensor with respect to the platform, specified as a three-element real-valued vector. Each element of the vector corresponds to an intrinsic Euler angle rotation that carries the body axes of the platform to the sensor axes. The three elements define the rotations around the z-, y-, and x-axes, in that order. The first rotation rotates the platform axes around the z-axis. The second rotation rotates the carried frame around the rotated y-axis. The final rotation rotates the frame around the carried x-axis. Units are in degrees.
Example: [10 20 -15]
Data Types: double
FieldOfView
— Fields of view of sensor
[10;50]
| 2-by-1 vector of positive scalar
Fields of view of sensor, specified as a 2-by-1 vector of positive scalars in degree,
[azfov;elfov]
. The field of view defines the total angular extent
spanned by the sensor. The azimuth field of view azfov
must lie in
the interval (0,360]. The elevation field of view elfov
must lie in
the interval (0,180].
Example: [14;7]
Data Types: double
ScanMode
— Scanning mode of sonar
'Electronic'
(default) | 'No scanning'
Scanning mode of sonar, specified as 'Electronic'
or
'No scanning'
.
Scan Modes
ScanMode | Purpose |
'Electronic' | The sonar scans electronically across the azimuth and
elevation limits specified by the
ElectronicScanLimits property.
The scan direction increments by the sonar field of view
angle between dwells. |
'No scanning' | The sonar beam points along the transducer boresight
defined by the mountingAngles
property. |
Example: 'No scanning'
Data Types: char
ElectronicScanLimits
— Angular limits of electronic scan directions of sonar
[-45 45;-45 45]
(default) | real-valued 1-by-2 row vector | real-valued 2-by-2 matrix
Angular limits of electronic scan directions of sonar, specified as a real-valued, 1-by-2 row vector or a real-valued 2-by-2 matrix. The electronic scan limits define the minimum and maximum electronic angles the sonar can scan from its current mechanical direction.
When HasElevation is true
, the scan limits
take the form [minAz maxAz; minEl maxEl]
.
minAz
and maxAz
represent the
minimum and maximum limits of the azimuth angle scan.
minEl
and maxEl
represent the
minimum and maximum limits of the elevation angle scan. When
HasElevation
is false
, the scan
limits take the form [minAz maxAz]
. If you specify the
scan limits as a 2-by-2 matrix but set HasElevation
to
false
, the second row of the matrix is
ignored.
Azimuthal scan limits and elevation scan limits must lie within the closed interval [-90° 90°]. Units are in degrees.
Example: [-90 90;0 85]
Dependencies
To enable this property, set the ScanMode
property to 'Electronic'
.
Data Types: double
ElectronicAngle
— Current electronic scan angle
electronic scalar | nonnegative scalar
This property is read-only.
Current electronic scan angle of sonar, returned as a scalar or 1-by-2
column vector. When HasElevation
is
true
, the scan angle takes the form
[Az;El]
. Az
and
El
represent the azimuth and elevation scan angles,
respectively. When HasElevation is false
, the scan angle is
a scalar representing the azimuth scan angle.
Dependencies
To enable this property, set the ScanMode
property to 'Electronic'
.
Data Types: double
HasElevation
— Enable sonar elevation scan and measurements
false
(default) | true
Enable the sonar to measure target elevation angles and to scan in
elevation, specified as false
or true
.
Set this property to true
to model a sonar sensor that
can estimate target elevation and scan in elevation.
Data Types: logical
CenterFrequency
— Center frequency of sonar band
20e3
(default) | positive scalar
Center frequency of sonar band, specified as a positive scalar. Units are in hertz.
Example: 25.5e3
Data Types: double
Bandwidth
— Sonar waveform bandwidth
2e3
| positive scalar
Sonar waveform bandwidth, specified as a positive scalar. Units are in hertz.
Example: 1.5e3
Data Types: double
WaveformTypes
— Detectable waveform types
0
(default) | nonnegative integer-valued L-element vector
Detectable waveform types, specified as a nonnegative integer-valued
L-element vector. Each integer represents a
detectable waveform type. When you specify the
sonarsigs
input arrangement, you can use the
WaveformType
property of a sonarEmission
object to specify the waveform type.
Example: [1 4 5]
Data Types: double
ConfusionMatrix
— Probability of correct classification of detected waveform
1
(default) | positive scalar | real-valued nonnegative L-element vector | real-valued nonnegative L-by-L
matrix
Probability of correct classification of a detected waveform, specified as
a positive scalar, a real-valued nonnegative L-element
vector, or a real-valued nonnegative
L-by-L matrix. Matrix values range
from 0 through 1 and matrix rows must sum to 1. L is the
number of waveform types that the sensor can detect, as indicated by the
value set in the WaveformTypes
property. The (i,j)
matrix element represents the probability of classifying the
ith waveform as the
jth waveform. When specified as a scalar from
0 through 1, the value is expanded along the diagonal of the confusion
matrix. When specified as a vector, it must have the same number of elements
as the WaveformTypes
property. When defined as a scalar
or a vector, the off diagonal values are set to (1-val)/(L-1).
Data Types: double
AmbientNoiseLevel
— Spectrum-level ambient isotropic noise
70
(default) | scalar
Spectrum-level ambient isotropic noise, specified as a scalar. Units are in dB relative to the intensity of a plane wave with 1 μPa rms pressure in a 1-hertz frequency band.
Example: 25
Data Types: double
FalseAlarmRate
— False alarm rate
1e-6
(default) | positive scalar
False alarm report rate within each resolution cell, specified as a positive scalar in the range [10–7,10–3]. Units are dimensionless. Resolution cells are determined from the AzimuthResolution property and the ElevationResolution property when enabled.
Example: 1e-5
Data Types: double
AzimuthResolution
— Azimuth resolution of sonar
1
(default) | positive scalar
Azimuth resolution of the sonar, specified as a positive scalar. The azimuth resolution defines the minimum separation in azimuth angle at which the sonar can distinguish two targets. The azimuth resolution is typically the 3-dB downpoint of the azimuth angle beamwidth of the sonar. Units are in degrees.
Data Types: double
ElevationResolution
— Elevation resolution of sonar
1
(default) | positive scalar
Elevation resolution of the sonar, specified as a positive scalar. The elevation resolution defines the minimum separation in elevation angle at which the sonar can distinguish two targets. The elevation resolution is typically the 3-dB downpoint in the elevation angle beamwidth of the sonar. Units are in degrees.
Dependencies
To enable this property, set the HasElevation
property to true
.
Data Types: double
RangeResolution
— Range resolution of sonar
100
(default) | positive scalar
Range resolution of the sonar, specified as a positive scalar. The range resolution defines the minimum separation in range at which the sonar can distinguish between two targets. Units are in meters.
Data Types: double
RangeRateResolution
— Range rate resolution of sonar
10
(default) | positive scalar
Range rate resolution of the sonar, specified as a positive scalar. The range rate resolution defines the minimum separation in range rate at which the sonar can distinguish between two targets. Units are in meters per second.
Dependencies
To enable this property, set the HasRangeRate
property to true
.
Data Types: double
AzimuthBiasFraction
— Azimuth bias fraction
0.1
(default) | nonnegative scalar
Azimuth bias fraction of the sonar, specified as a nonnegative scalar. The
azimuth bias is expressed as a fraction of the azimuth resolution specified
in AzimuthResolution
. This value sets a lower bound on
the azimuthal accuracy of the sonar. This value is dimensionless.
Data Types: double
ElevationBiasFraction
— Elevation bias fraction
0.1
(default) | nonnegative scalar
Elevation bias fraction of the sonar, specified as a nonnegative scalar.
Elevation bias is expressed as a fraction of the elevation resolution
specified by the value of the ElevationResolution
property. This value sets a lower bound on the elevation accuracy of the
sonar. This value 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 sonar, specified as a nonnegative scalar. Range
bias is expressed as a fraction of the range resolution specified in
RangeResolution
. This property sets a lower bound
on the range accuracy of the sonar. This value is dimensionless.
Data Types: double
RangeRateBiasFraction
— Range rate bias fraction
0.05
(default) | nonnegative scalar
Range rate bias fraction of the sonar, specified as a nonnegative scalar.
Range rate bias is expressed as a fraction of the range rate resolution
specified in RangeRateResolution
. This property sets a
lower bound on the range-rate accuracy of the sonar. This value is
dimensionless.
Dependencies
To enable this property, set the HasRangeRate
property to true
.
Data Types: double
HasRangeRate
— Enable sonar to measure range rate
false
(default) | true
Enable the sonar to measure target range rates, specified as
false
or true
. Set this property
to true
to model a sonar sensor that can measure target
range rate. Set this property to false
to model a sonar
sensor that cannot measure range rate.
Data Types: logical
HasRangeAmbiguities
— Enable range ambiguities
false
(default) | true
Enable range ambiguities, specified as false
or
true
. Set this property to true
to
enable range ambiguities by the sensor. In this case, the sensor cannot
resolve range ambiguities for targets at ranges beyond the MaxUnambiguousRange are wrapped into the interval
[0 MaxUnambiguousRange]
. When
false
, targets are reported at their unambiguous
range.
Data Types: logical
HasRangeRateAmbiguities
— Enable range-rate ambiguities
false
(default) | true
Enable range-rate ambiguities, specified as false
or
true
. Set to true
to enable
range-rate ambiguities by the sensor. When true
, the
sensor does not resolve range rate ambiguities and target range rates beyond
the MaxUnambiguousRadialSpeed
are wrapped into the
interval [0,MaxUnambiguousRadialSpeed]
. When
false
, targets are reported at their unambiguous
range rate.
Dependencies
To enable this property, set the HasRangeRate property to true
.
Data Types: logical
MaxUnambiguousRange
— Maximum unambiguous detection range
100e3
(default) | positive scalar
Maximum unambiguous range, specified as a positive scalar. Maximum
unambiguous range defines the maximum range for which the sonar 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]
. This
property applies to true target detections when you set the
HasRangeAmbiguities
property to
true
.
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 for false
alarms.
Units are in meters.
Example: 5e3
Dependencies
To enable this property, set the
HasRangeAmbiguities
property to
true
or set the
HasFalseAlarms
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 sonar 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]
. This property applies to true
target detections when you set HasRangeRateAmbiguities
property to true
.
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 for which false alarms can be generated.
Units are in meters per second.
Dependencies
To enable this property, set HasRangeRate
and
HasRangeRateAmbiguities
to
true
and/or set HasRangeRate
and HasFalseAlarms
to
true
.
Data Types: double
HasINS
— Enable inertial navigation system (INS) input
false
(default) | true
Enable the optional input argument that passes the current estimate of the
sensor platform pose to the sensor, specified as false
or
true
. When true
, pose information
is added to the MeasurementParameters
structure of the
reported detections. Pose information lets tracking and fusion algorithms
estimate the state of the target detections in the north-east-down (NED)
frame.
Data Types: logical
HasNoise
— Enable addition of noise to sonar sensor measurements
true
(default) | false
Enable addition of noise to sonar sensor measurements, specified as
true
or false
. Set this property
to true
to add noise to the sonar measurements.
Otherwise, the measurements have no noise. Even if you set
HasNoise
to false
, the object
still computes the MeasurementNoise
property of each
detection.
Data Types: logical
HasFalseAlarms
— Enable creating false alarm sonar detections
true
(default) | false
Enable creating false alarm sonar measurements, specified as
true
or false
. Set this property
to true
to report false alarms. Otherwise, only actual
detections are reported.
Data Types: logical
MaxNumDetectionsSource
— Source of maximum number of detections reported
'Auto'
(default) | 'Property'
Source of maximum number of detections reported by the sensor, specified
as 'Auto'
or 'Property'
. When this
property is set to 'Auto'
, the sensor reports all
detections. When this property is set to 'Property'
, the
sensor reports up to the number of detections specified by the
MaxNumDetections
property.
Data Types: char
MaxNumDetections
— Maximum number of reported detections
50
(default) | positive integer
Maximum number of detections reported by the sensor, specified as a positive integer. Detections are reported in order of distance to the sensor until the maximum number is reached.
Dependencies
To enable this property, set the
MaxNumDetectionsSource
property to
'Property'
.
Data Types: double
DetectionCoordinates
— Coordinate system of reported detections
'Body'
(default) | 'Scenario'
| 'Sensor rectangular
| 'Sensor spherical'
Coordinate system of reported detections, specified as:
'Scenario'
— Detections are reported in the rectangular scenario coordinate frame. The scenario coordinate system is defined as the local NED frame at simulation start time. To enable this value, set theHasINS
property totrue
.'Body'
— Detections are reported in the rectangular body system of the sensor platform.'Sensor rectangular'
— Detections are reported in the sonar 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 sonar sensor and aligned with the orientation of the sonar on the platform.
Example: 'Sensor spherical'
Data Types: char
Usage
Syntax
Description
Input Arguments
sonarsigs
— Sonar emissions
array of sonar emission objects
Sonar emissions, specified as an array of sonarEmission
objects.
txconfigs
— Emitter configurations
array of structures
Emitter configurations, specified as an array of structures. Each structure has these fields:
Field | Description |
EmitterIndex | Unique emitter index, returned as a positive integer. |
IsValidTime | Valid emission time, returned as |
IsScanDone | Whether the emitter has completed a scan, returned as |
FieldOfView | Field of view of the emitter, returned as a two-element vector [azimuth; elevation] in degrees. |
MeasurementParameters | Emitter 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 emitter looking-angle frame. |
Data Types: struct
ins
— Platform pose from INS
structure
Sensor platform pose obtained from the inertial navigation system (INS), specified as a structure.
Platform pose information from an inertial navigation system (INS) is a structure with these fields:
Field | Definition |
Position | Position in the navigation frame, specified as a real-valued 1-by-3 vector. Units are in meters. |
Velocity | Velocity in the navigation frame, specified as a real-valued 1-by-3 vector. Units are in meters per second. |
Orientation | Orientation with respect to the navigation frame, specified as
a |
Dependencies
To enable this argument, set the HasINS
property to true
.
Data Types: struct
simTime
— Current simulation time
nonnegative scalar
Current simulation time, specified as a positive scalar. The trackingScenario
object calls the sonar sensor at regular
time intervals. The sonar sensor generates new detections at intervals
defined by the UpdateInterval
property. The value
of the UpdateInterval
property must be an integer
multiple of the simulation time interval. Updates requested from the
sensor between update intervals contain no detections. Units are in
seconds.
Example: 10.5
Data Types: double
Output Arguments
dets
— sensor detections
cell array of objectDetection
objects
Sensor detections, returned as a cell array of objectDetection
objects.
Each object has these properties:
Property | Definition |
---|---|
Time | Measurement time |
Measurement | Object measurements |
MeasurementNoise | Measurement noise covariance matrix |
SensorIndex | Unique ID of the sensor |
ObjectClassID | Object classification |
MeasurementParameters | Parameters used by initialization functions of nonlinear Kalman tracking filters |
ObjectAttributes | Additional information passed to tracker |
Measurement
and
MeasurementNoise
are reported in the coordinate
system specified by the DetectionCoordinates
property.
numDets
— Number of detections
nonnegative integer
Number of detections reported, returned as a nonnegative integer.
When the
MaxNumDetectionsSource
property is set to'Auto'
,numDets
is set to the length ofdets
.When the
MaxNumDetectionsSource
property is set to'Property'
,dets
is a cell array with length determined by theMaxNumDetections
property. No more thanMaxNumDetections
number of detections are returned. If the number of detections is fewer thanMaxNumDetections
, the firstnumDets
elements ofdets
hold valid detections. The remaining elements ofdets
are set to the default value.
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 sonar beam during object execution.
Field | Description |
SensorIndex | Unique sensor index, returned as a positive integer. |
IsValidTime | Valid detection time, returned as |
IsScanDone |
|
RangeLimits | Lower and upper range detection limits, returned as a two-element real-valued vector in meters. |
RangeRateLimits | Lower and upper range-rate detection limits, returned as a two-element real-valued vector in m/s. |
FieldOfView | Field of view of the sensor, returned as a 2-by-1 vector of positive real values, [ |
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 looking-angle 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 sonarSensor
coverageConfig | Sensor and emitter coverage configuration |
perturbations | Perturbation defined on object |
perturb | Apply perturbations to object |
Examples
Detect Sonar Emission with Passive Sensor
Create a sonar emission and then detect the emission using a sonarSensor
object.
First, create a sonar emission.
orient = quaternion([180 0 0],'eulerd','zyx','frame'); sonarSig = sonarEmission('PlatformID',1,'EmitterIndex',1, ... 'OriginPosition',[30 0 0],'Orientation',orient, ... 'SourceLevel',140,'TargetStrength',100);
Then create a passive sonar sensor.
sensor = sonarSensor(1,'No scanning');
Detect the sonar emission.
time = 0; [dets, numDets, config] = sensor(sonarSig,time)
dets = 1x1 cell array
{1x1 objectDetection}
numDets = 1
config = struct with fields:
SensorIndex: 1
IsValidTime: 1
IsScanDone: 1
FieldOfView: [1 5]
RangeLimits: [0 Inf]
RangeRateLimits: [0 Inf]
MeasurementParameters: [1x1 struct]
More About
Object Detections
The sensor measures the coordinates of the target. The Measurement
and MeasurementNoise
values are reported in the coordinate system
specified by the DetectionCoordinates
property of the sensor.
When the DetectionCoordinates
property is
'Scenario'
, 'Body'
, or 'Sensor
rectangular'
, the Measurement
and
MeasurementNoise
values are reported in rectangular coordinates.
Velocities are only reported when the range rate property,
HasRangeRate
, is true
.
When the DetectionCoordinates
property is 'Sensor
spherical'
, the Measurement
and
MeasurementNoise
values are reported in a spherical coordinate
system derived from the sensor rectangular coordinate system. Elevation and range rate are
only reported when HasElevation
and HasRangeRate
are true
.
Measurements are ordered as [azimuth, elevation, range, range rate]. Reporting of
elevation and range rate depends on the corresponding HasElevation
and
HasRangeRate
property values. Angles are in degrees, range is in
meters, and range rate is in meters per second.
Measurement Coordinates
DetectionCoordinates | Measurement and Measurement Noise Coordinates | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
'Scenario' | Coordinate Dependence on
| |||||||||||||||
'Body' | ||||||||||||||||
'Sensor rectangular' | ||||||||||||||||
'Sensor spherical' | Coordinate Dependence on
|
The MeasurementParameters
property consists of an array of structures
that describe a sequence of coordinate transformations from a child frame to a parent frame
or the inverse transformations (see Frame Rotation). 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 the 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 form the scenario frame to the platform frame then
from 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.
Trivially, if the detections are reported in platform rectangular coordinates and
HasINS
is set to false
, the transformation
consists only of the identity.
The fields of MeasurementParameters
are shown here. Not all fields have
to be present in the structure. The 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, |
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 | A logical scalar indicating if |
HasElevation | A logical scalar indicating if elevation is included in the
measurement. For measurements reported in a rectangular frame, and
if |
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 the rectangular
frame, if |
Object attributes contain additional information about a detection.
Attribute | Description |
TargetIndex | Identifier of the platform, |
EmitterIndex | Index of the emitter from which the detected signal was emitted. |
SNR | Detection signal-to-noise ratio in dB. |
CenterFrequency |
|
Bandwidth |
|
WaveformType |
|
Convenience Syntaxes
The convenience syntaxes set several properties together to model a specific type of sonar.
Sets ScanMode
to 'No scanning'.
This syntax sets these properties:
Property | Value |
ScanMode | 'Electronic' |
HasElevation | true |
ElectronicScanLimits | [-45 45; -10 0] |
FieldOfView | [1;5] |
This syntax sets these properties:
Property | Value |
ScanMode | 'Electronic' |
HasElevation | false |
ElectronicScanLimits | [-45 45] |
FieldOfView | [1;10] |
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
The object functions, perturbations
and perturb
, do not support code generation.
Usage notes and limitations:
See System Objects in MATLAB Code Generation (MATLAB Coder).
Version History
Introduced in R2018b
MATLAB Command
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