Constant Gamma Clutter
Libraries:
Radar Toolbox
Description
The Constant Gamma Clutter block generates constant gamma clutter reflected from homogeneous terrain for a monostatic radar transmitting a narrowband signal into free space. The radar is assumed to be at constant altitude moving at constant speed.
Ports
Input
PRFIdx — PRF Index
positive integer
Index to select the pulse repetition frequency (PRF), specified as a positive integer. The index selects the PRF from the predefined vector of values specified by the Pulse repetition frequency (Hz) parameter.
Example:
4
Dependencies
To enable this port, select Enable PRF selection input.
Data Types: double
W — Element weights
length-N complex-valued vector
Weights applied to each element in array, specified as a length-N complex-valued vector. N is the number of elements in the array selected in the Sensor array panel.
Dependencies
To enable this port, select the Enable weights input check box.
Data Types: double
Complex Number Support: Yes
WS — Subarray element weights
NE-by-NS
complex-valued matrix
Weights applied to each element in a subarray, specified as an NE-by-NS complex-valued matrix.
When you set Specify sensor array to
Replicated Subarray
, all subarrays have the same dimensions. Then, you can specify the subarray element weights as a complex-valued NE-by-NS matrix. NE is the number of elements in each subarray and NS is the number of subarrays. Each column ofWS
specifies the weights for the corresponding subarray.When you set Specify sensor array to
Partitioned array
, subarrays are not required to have identical dimensions and sizes. You can specify subarray element weights as a complex-valued NE-by-NS matrix, where NE now is the number of elements in the largest subarray. The first K entries in each column are the element weights for the corresponding subarray where K is the number of elements in the subarray.
Dependencies
To enable this port, set Specify sensor array
to Partitioned array
or
Replicated Subarray
. Then, set
Subarray steering method to
Custom
.
Data Types: double
Complex Number Support: Yes
Steer — Steering angle input
scalar | 2-by-1 real-valued vector
Steering angle, specified as a scalar or a 2-by-1 real-valued vector.
As a vector, the steering angle takes the form of
[AzimuthAngle; ElevationAngle]
. As a scalar, the
steering angle represents the azimuth angle only. Then the elevation
angle is assumed to be zero degrees. Units are in degrees
Dependencies
To enable this port, set Specify sensor array
to Partitioned array
or
Replicated Subarray
. Then, set
Subarray steering method to
Phase
or
Time
.
Data Types: double
Output
Out — Simulated clutter
N-by-M complex-valued
matrix
Simulated clutter, returned as an N-by-M complex-valued matrix.
N is the number of samples output from the block.
When you set the Output signal format parameter to
Samples
, specify N
using the Number of samples in output parameter.
When you set the Output signal format parameter to
Pulses
, N is the total
number of samples in the next P pulses where
P is specified in the Number of pulse
in output parameter.
M is either
the number of subarrays in the sensor array if sensor array contains subarrays.
the number of radiating or collecting elements if the sensor array does not contain subarrays.
Data Types: double
Parameters
Main Tab
Terrain gamma value (dB) — Clutter model parameter
0
(default) | scalar
Clutter model parameter, specified as a scalar. This parameter contains the value used in the constant clutter model. The value depends on both terrain type and the operating frequency. Units are in dB.
Example: -5.0
Data Types: double
Earth model — Earth shape
Flat
(default) | Curved
Specify the earth model used in clutter simulation as
Flat
or
Curved
. When you set this parameter to
Flat
, the earth is assumed to be a plane.
When you set this parameter to Curved
, the
earth is assumed to be spherical.
Minimum range of clutter region (m) — Minimum range of clutter region
0
| nonnegative scalar
Specify the minimum range for the clutter simulation as a positive scalar. The minimum range must be nonnegative. Units are in meters.
Maximum range of clutter region (m) — Maximum range of clutter region
5000
| nonnegative scalar
Specify the maximum range for the clutter simulation as a positive
scalar. The maximum range must be greater than the value specified in
the Radar height
parameter. Units are in
meters.
Azimuth center of clutter region (deg) — Azimuth center of clutter region
0
| scalar
The azimuth angle in the ground plane about which clutter patches are generated. Patches are generated symmetrically about this angle. Units are in degrees.
Azimuth span of clutter region (deg) — Azimuth span of clutter region
60
(default) | positive scalar
Specify the azimuth span of each clutter patch as a positive scalar. Units are in degrees. Units are in degrees.
Azimuth span of clutter patches (deg) — Azimuth span of clutter patches
1
(default) | positive scalar
Azimuth span of each clutter patch, specified as a positive scalar. Units are in degrees.
Data Types: double
Clutter coherence time (s) — Coherence time of clutter simulation
Inf
(default) | positive scalar
Coherence time for the clutter simulation, specified as a positive
scalar. After the coherence time elapses, the block updates the random
numbers it uses for the clutter simulation at the next pulse. When you
use the default value of Inf
, the random numbers are
never updated. Units are in seconds.
Example: 4
Data Types: double
Signal propagation speed (m/s) — Signal propagation speed
physconst('LightSpeed')
(default) | real-valued positive scalar
Signal propagation speed, specified as a real-valued positive scalar. The default value of the
speed of light is the value returned by physconst('LightSpeed')
.
Units are in meters per second.
Example: 3e8
Data Types: double
Sample rate (Hz) — Clutter sample rate
1e6
(default) | positive scalar
Clutter sample rate, specified as a positive scalar. Units are in Hertz.
Example: 10e6
Data Types: double
Pulse repetition frequency (Hz) — Pulse repetition frequency
1e4
(default) | positive scalar | row vector of positive values
Pulse repetition frequency, PRF, specified as a positive scalar or a row vector of positive values. Units are in Hertz.
Example: [1e4,2e4]
Data Types: double
Enable PRF selection input — Select predefined PRF
off (default) | on
Select this parameter to enable the PRFIdx
port.
When enabled, pass in an index into a vector of predefined PRFs. Set predefined PRFs using the Pulse repetition frequency (Hz) parameter.
When not enabled, the block cycles through the vector of PRFs specified by the Pulse repetition frequency (Hz) parameter. If Pulse repetition frequency (Hz) is a scalar, the PRF is constant.
Source of simulation sample time — Source of simulation sample time
Derive from waveform parameters
(default) | Inherit from Simulink engine
Source of simulation sample time, specified as Derive from waveform
parameters
or Inherit from Simulink engine
.
When set to Derive from waveform parameters
, the block runs
at a variable rate determined by the PRF of the selected waveform. The elapsed time is
variable. When set to Inherit from Simulink engine
, the
block runs at a fixed rate so the elapsed time is a constant.
Dependencies
To enable this parameter, select the Enable PRF selection input parameter.
Output signal format — Format of the output signal
Pulses
(default) | Samples
The format of the output signal, specified as Pulses
or Samples
.
If you set this parameter to Samples
, the output of the block consists of multiple samples. The number of samples is the value of the Number of samples in output parameter.
If you set this parameter to Pulses
, the output of the block consists of multiple pulses. The number of pulses is the value of the Number of pulses in output parameter.
Number of samples in output — Number of samples in output
100
(default) | positive integer
Number of samples in the block output, specified as a positive integer.
Example: 1000
Dependencies
To enable this parameter, set the Output signal format
parameter to Samples
.
Data Types: double
Number of pulses in output — Number of pulses in output
1
(default) | positive integer
Number of pulses in the block output, specified as a positive integer.
Example: 2
Dependencies
To enable this parameter, set the Output signal
format parameter to
Pulses
.
Data Types: double
Simulate using — Block simulation method
Interpreted Execution
(default) | Code Generation
Block simulation, specified as Interpreted Execution
or Code
Generation
. If you want your block to use the MATLAB® interpreter,
choose Interpreted Execution
. If you want
your block to run as compiled code, choose Code Generation
.
Compiled code requires time to compile but usually runs faster.
Interpreted execution is useful when you are developing and tuning a model. The block runs the
underlying System object™ in MATLAB. You can change and execute your model quickly. When you are satisfied
with your results, you can then run the block using Code
Generation
. Long simulations run faster with generated code than in
interpreted execution. You can run repeated executions without recompiling, but if you
change any block parameters, then the block automatically recompiles before
execution.
This table shows how the Simulate using parameter affects the overall simulation behavior.
When the Simulink® model is in Accelerator
mode, the block mode specified
using Simulate using overrides the simulation mode.
Acceleration Modes
Block Simulation | Simulation Behavior | ||
Normal | Accelerator | Rapid Accelerator | |
Interpreted Execution | The block executes using the MATLAB interpreter. | The block executes using the MATLAB interpreter. | Creates a standalone executable from the model. |
Code Generation | The block is compiled. | All blocks in the model are compiled. |
For more information, see Choosing a Simulation Mode (Simulink).
Operating frequency (Hz) — System operating frequency
3.0e8
(default) | positive real scalar
System operating frequency, specified as a positive scalar. Units are in Hz.
Effective transmitted power (W) — radar system effective transmitted power
5000
(default) | positive scalar
Effective radiated power (ERP) of the radar system, specified as a positive scalar. Units are in watts.
Example: 3500
Data Types: double
Radar height (m) — Height of radar above surface
0
(default) | nonnegative scalar
Height of radar above surface, specified as a nonnegative scalar. Units are in meters.
Example: 50
Data Types: double
Radar speed (m/s) — Radar platform speed
0
(default) | nonnegative scalar
Radar platform speed, specified as a nonnegative scalar. Units are in meters per second.
Example: 5
Data Types: double
Radar motion direction (deg) — Direction of motion of radar platform
[90;0]
(default) | 2-by-1 real vector
Specify the direction of radar platform motion as a 2-by-1 real vector
in the form [AzimuthAngle;ElevationAngle]
. Units are
in degrees. Both azimuth and elevation angle are measured in the local
coordinate system of the radar antenna or antenna array. Azimuth angle
must be between –180° and 180°. Elevation angle must be
between –90° and 90°.
The default value of this parameter indicates that the radar platform is moving perpendicular to the radar antenna array broadside direction.
Example: [25;30]
Data Types: double
Sensor mounting angles sensor (deg) — Sensor mounting angles
[0 0 0]
(default) | length-3 vector of positive values
Specify a 3-element vector that gives the intrinsic yaw, pitch, and roll of the sensor frame from the inertial frame. The 3 elements define the rotations around the z, y, and x axes respectively, in that order. The first rotation, rotates the body axes around the z-axis. Because these angles define intrinsic rotations, the second rotation is performed around the y-axis in its new position resulting from the previous rotation. The final rotation around the x-axis is performed around the x-axis as rotated by the first two rotations in the intrinsic system.
Example: [0,-10,4]
Data Types: double
Enable weights input — Enable antenna element weights input port
unchecked (default) | checked
Check box to enable antenna element weights input port,
W
.
Sensor Array Tab
Specify sensor array as — Method to specify array
Array (no subarrays)
(default) | Partitioned array
| Replicated subarray
| MATLAB expression
Method to specify array, specified as Array (no
subarrays)
or MATLAB expression
.
Array (no subarrays)
— use the block parameters to specify the array.Partitioned array
— use the block parameters to specify the array.Replicated subarray
— use the block parameters to specify the array.MATLAB expression
— create the array using a MATLAB expression.
Expression — MATLAB expression used to create an array
Phased Array System Toolbox™ array System object
MATLAB expression used to create an array, specified as a valid Phased Array System Toolbox array System object.
Example: phased.URA('Size',[5,3])
Dependencies
To enable this parameter, set Specify sensor array
as to MATLAB expression
.
Element type — Array element types
Isotropic Antenna
(default) | Cosine Antenna
| Custom Antenna
| Omni Microphone
| Custom Microphone
Antenna or microphone type, specified as one of the following:
Isotropic Antenna
Cosine Antenna
Custom Antenna
Omni Microphone
Custom Microphone
Operating frequency range (Hz) — Operating frequency range of the antenna or microphone element
[0,1.0e20]
(default) | real-valued 1-by-2 row vector
Specify the operating frequency range of the antenna or microphone
element as a 1-by-2 row vector in the form [LowerBound,UpperBound]
.
The element has no response outside this frequency range. Frequency
units are in Hz.
Dependencies
To enable this parameter, set Element type to Isotropic
Antenna
, Cosine Antenna
, or Omni
Microphone
.
Operating frequency vector (Hz) — Operating frequency range of custom antenna or microphone elements
[0,1.0e20]
(default) | real-valued row vector
Specify the frequencies at which to set antenna and microphone frequency responses as a 1-by-L row vector of increasing real values. The antenna or microphone element has no response outside the frequency range specified by the minimum and maximum elements of this vector. Frequency units are in Hz.
Dependencies
To enable this parameter, set Element type to Custom
Antenna
or Custom Microphone
. Use Frequency
responses (dB) to set the responses at these frequencies.
Baffle the back of the element — Set back response of an Isotropic Antenna
element or an Omni Microphone
element to zero
off (default) | on
Select this check box to baffle the back response of the element. When back baffled, the responses at all azimuth angles beyond ±90° from broadside are set to zero. The broadside direction is defined as 0° azimuth angle and 0° elevation angle.
Dependencies
To enable this check box, set Element type to Isotropic
Antenna
or Omni Microphone
.
Exponent of cosine pattern — Exponents of azimuth and elevation cosine patterns
[1.5 1.5]
(default) | nonnegative scalar | real-valued 1-by-2 matrix of nonnegative values
Specify the exponents of the cosine pattern as a nonnegative scalar or a real-valued 1-by-2 matrix of nonnegative values. When Exponent of cosine pattern is a 1-by-2 vector, the first element is the exponent in the azimuth direction and the second element is the exponent in the elevation direction. When you set this parameter to a scalar, both the azimuth direction and elevation direction cosine patterns are raised to the same power.
Dependencies
To enable this parameter, set Element type to Cosine
Antenna
.
Frequency responses (dB) — Antenna and microphone frequency response
[0,0]
(default) | real-valued row vector
Frequency response of a custom antenna or custom microphone for the frequencies defined by the Operating frequency vector (Hz) parameter. The dimensions of Frequency responses (dB) must match the dimensions of the vector specified by the Operating frequency vector (Hz) parameter.
Dependencies
To enable this parameter, set Element type to Custom
Antenna
or Custom Microphone
.
Input Pattern Coordinate System — Coordinate system of custom antenna pattern
az-el
(default) | phi-theta
Coordinate system of custom antenna pattern, specified az-el
or phi-theta
. When you specify az-el
, use the Azimuth angles (deg) and Elevations angles (deg) parameters to specify the coordinates of the pattern points. When you specify phi-theta
, use the Phi angles (deg) and Theta angles (deg) parameters to specify the coordinates of the pattern points.
Dependencies
To enable this parameter, set Element type to Custom Antenna
.
Azimuth angles (deg) — Azimuth angles of antenna radiation pattern
[-180:180]
(default) | real-valued row vector
Specify the azimuth angles at which to calculate the antenna radiation pattern as a 1-by-P row vector. P must be greater than 2. Azimuth angles must lie between –180° and 180°, inclusive, and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to
Custom Antenna
and the Input Pattern Coordinate
System parameter to az-el
.
Elevation angles (deg) — Elevation angles of antenna radiation pattern
[-90:90]
(default) | real-valued row vector
Specify the elevation angles at which to compute the radiation pattern as a 1-by-Q vector. Q must be greater than 2. Angle units are in degrees. Elevation angles must lie between –90° and 90°, inclusive, and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to
Custom Antenna
and the Input Pattern Coordinate
System parameter to az-el
.
Phi Angles (deg) — Phi angle coordinates of custom antenna radiation pattern
0:360
| real-valued 1-by-P row vector
Phi angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-P row vector. P must be greater than 2. Angle units are in degrees. Phi angles must lie between 0° and 360° and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to Custom Antenna
and the Input Pattern Coordinate System parameter to phi-theta
.
Theta Angles (deg) — Theta angle coordinates of custom antenna radiation pattern
0:180
| real-valued 1-by-Q row vector
Theta angles of points at which to specify the antenna radiation pattern, specify as a real-valued 1-by-Q row vector. Q must be greater than 2. Angle units are in degrees. Theta angles must lie between 0° and 360° and be in strictly increasing order.
Dependencies
To enable this parameter, set the Element type parameter to Custom Antenna
and the Input Pattern Coordinate System parameter to phi-theta
.
Magnitude pattern (dB) — Magnitude of combined antenna radiation pattern
zeros(181,361)
(default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L array
Magnitude of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.
When the Input Pattern Coordinate System parameter is set to
az-el
, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.When the Input Pattern Coordinate System parameter is set to
phi-theta
, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.
The quantity L equals the length of the Operating frequency vector (Hz).
If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.
If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (Hz) parameter.
Dependencies
To enable this parameter, set Element type to
Custom Antenna
.
Phase pattern (deg) — Custom antenna radiation phase pattern
zeros(181,361)
(default) | real-valued Q-by-P matrix | real-valued Q-by-P-by-L array
Phase of the combined antenna radiation pattern, specified as a Q-by-P matrix or a Q-by-P-by-L array.
When the Input Pattern Coordinate System parameter is set to
az-el
, Q equals the length of the vector specified by the Elevation angles (deg) parameter and P equals the length of the vector specified by the Azimuth angles (deg) parameter.When the Input Pattern Coordinate System parameter is set to
phi-theta
, Q equals the length of the vector specified by the Theta Angles (deg) parameter and P equals the length of the vector specified by the Phi Angles (deg) parameter.
The quantity L equals the length of the Operating frequency vector (Hz).
If this parameter is a Q-by-P matrix, the same pattern is applied to all frequencies specified in the Operating frequency vector (Hz) parameter.
If the value is a Q-by-P-by-L array, each Q-by-P page of the array specifies a pattern for the corresponding frequency specified in the Operating frequency vector (
Dependencies
To enable this parameter, set Element type to
Custom Antenna
.
MatchArrayNormal — Rotate antenna element to array normal
on
(default) | off
Select this check box to rotate the antenna element pattern to align with the array normal. When not selected, the element pattern is not rotated.
When the antenna is used in an antenna array and the Input Pattern Coordinate System parameter is az-el
, selecting this check box rotates the pattern so that the x-axis of the element coordinate system points along the array normal. Not selecting uses the element pattern without the rotation.
When the antenna is used in an antenna array and Input Pattern Coordinate System is set to phi-theta
, selecting this check box rotates the pattern so that the z-axis of the element coordinate system points along the array normal.
Use the parameter in conjunction with the Array normal parameter of the URA
and UCA
arrays.
Dependencies
To enable this parameter, set Element type to Custom Antenna
.
Polar pattern frequencies (Hz) — Polar pattern microphone response frequencies
1e3 (default) | real scalar | real-valued 1-by-L row vector
Polar pattern microphone response frequencies, specified as a real scalar, or a real-valued, 1-by-L vector. The response frequencies lie within the frequency range specified by the Operating frequency vector (Hz) vector.
Dependencies
To enable this parameter, set Element type set to
Custom Microphone
.
Polar pattern angles (deg) — Polar pattern response angles
[-180:180]
(default) | real-valued -by-P row vector
Specify the polar pattern response angles, as a 1-by-P vector. The angles are measured from the central pickup axis of the microphone and must be between –180° and 180°, inclusive.
Dependencies
To enable this parameter, set Element type to Custom
Microphone
.
Polar pattern (dB) — Custom microphone polar response
zeros(1,361)
(default) | real-valued L-by-P matrix
Specify the magnitude of the custom microphone element polar patterns as an L-by-P matrix. L is the number of frequencies specified in Polar pattern frequencies (Hz). P is the number of angles specified in Polar pattern angles (deg). Each row of the matrix represents the magnitude of the polar pattern measured at the corresponding frequency specified in Polar pattern frequencies (Hz) and all angles specified in Polar pattern angles (deg). The pattern is measured in the azimuth plane. In the azimuth plane, the elevation angle is 0° and the central pickup axis is 0° degrees azimuth and 0° degrees elevation. The polar pattern is symmetric around the central axis. You can construct the microphone response pattern in 3-D space from the polar pattern.
Dependencies
To enable this parameter, set Element type to Custom
Microphone
.
Geometry — Array geometry
ULA
(default) | URA
| UCA
| Conformal Array
Array geometry, specified as one of
ULA
— Uniform linear arrayURA
— Uniform rectangular arrayUCA
— Uniform circular arrayConformal Array
— arbitrary element positions
Number of elements — Number of array elements
2
for ULA arrays and 5
for
UCA arrays (default) | integer greater than or equal to 2
The number of array elements for ULA or UCA arrays, specified as an integer greater than or equal to 2.
When you set Specify sensor array as to Replicated
subarray
, this parameter applies to each subarray.
Dependencies
To enable this parameter, set Geometry to ULA
or UCA
.
Element spacing (m) — Spacing between array elements
0.5
for ULA arrays and [0.5,0.5]
for
URA arrays (default) | positive scalar for ULA or URA arrays | 2-element vector of positive values for URA arrays
Spacing between adjacent array elements:
ULA — specify the spacing between two adjacent elements in the array as a positive scalar.
URA — specify the spacing as a positive scalar or a 1-by-2 vector of positive values. If Element spacing (m) is a scalar, the row and column spacings are equal. If Element spacing (m) is a vector, the vector has the form
[SpacingBetweenArrayRows,SpacingBetweenArrayColumns]
.When you set Specify sensor array as to
Replicated subarray
, this parameter applies to each subarray.
Dependencies
To enable this parameter, set Geometry to ULA
or URA
.
Array axis — Linear axis direction of ULA
y
(default) | x
| z
Linear axis direction of ULA, specified as y
, x
,
or z
. All ULA array elements are uniformly
spaced along this axis in the local array coordinate system.
Dependencies
To enable this parameter, set Geometry to
ULA
.This parameter is also enabled when the block only supports ULA arrays.
Array size — Dimensions of URA array
[2,2]
(default) | positive integer | 1-by-2 vector of positive integers
Dimensions of a URA array, specified as a positive integer or 1-by-2 vector of positive integers.
If Array size is a 1-by-2 vector, the vector has the form
[NumberOfArrayRows,NumberOfArrayColumns]
.If Array size is an integer, the array has the same number of rows and columns.
When you set Specify sensor array as to
Replicated subarray
, this parameter applies to each subarray.
For a URA, array elements are indexed from top to bottom along the
leftmost column, and then continue to the next columns from left to right. In this
figure, the Array size value of [3,2]
creates an
array having three rows and two columns.
Dependencies
To enable this parameter, set Geometry to URA
.
Element lattice — Lattice of URA element positions
Rectangular
(default) | Triangular
Lattice of URA element positions, specified as Rectangular
or Triangular
.
Rectangular
— Aligns all the elements in row and column directions.Triangular
— Shifts the even-row elements of a rectangular lattice toward the positive row-axis direction. The displacement is one-half the element spacing along the row dimension.
Dependencies
To enable this parameter, set Geometry to URA
.
Array normal — Array normal direction
x
for URA arrays
or z
for UCA arrays (default) | y
Array normal direction, specified as x
, y
,
or z
.
Elements of planar arrays lie in a plane orthogonal to the selected array normal direction. Element boresight directions point along the array normal direction.
Array Normal Parameter Value | Element Positions and Boresight Directions |
---|---|
x | Array elements lie in the yz-plane. All element boresight vectors point along the x-axis. |
y | Array elements lie in the zx-plane. All element boresight vectors point along the y-axis. |
z | Array elements lie in the xy-plane. All element boresight vectors point along the z-axis. |
Dependencies
To enable this parameter, set Geometry to URA
or UCA
.
Radius of UCA (m) — UCA array radius
0.5 (default) | positive scalar
Radius of UCA array, specified as a positive scalar.
Dependencies
To enable this parameter, set Geometry to UCA
.
Element positions (m) — Positions of conformal array elements
[0;0;0]
(default) | 3-by-Nmatrix of real values
Positions of the elements in a conformal array, specified as
a 3-by-N matrix of real values, where N is
the number of elements in the conformal array. Each column of this
matrix represents the position [x;y;z]
of an array
element in the array local coordinate system. The origin of the local
coordinate system is (0,0,0). Units are in meters.
When you set Specify sensor array as to Replicated
subarray
, this parameter applies to each subarray.
Dependencies
To enable this parameter set Geometry to Conformal
Array
.
Element normals (deg) — Direction of conformal array element normal vectors
[0;0]
| 2-by-1 column vector | 2-by-N matrix
Direction of element normal vectors in a conformal array, specified as a 2-by-1 column vector
or a 2-by-N matrix. N indicates the number of
elements in the array. For a matrix, each column specifies the normal direction of the
corresponding element in the form [azimuth;elevation]
with respect to
the local coordinate system. The local coordinate system aligns the positive
x-axis with the direction normal to the conformal array. If the
parameter value is a 2-by-1 column vector, the same pointing direction is used for all
array elements.
When you set Specify sensor array as to Replicated
subarray
, this parameter applies to each subarray.
You can use the Element positions (m) and Element normals (deg) parameters to represent any arrangement in which pairs of elements differ by certain transformations. The transformations can combine translation, azimuth rotation, and elevation rotation. However, you cannot use transformations that require rotation about the normal direction.
Dependencies
To enable this parameter, set Geometry to Conformal
Array
.
Taper — Array element tapers
1 (default) | complex-valued scalar | complex-valued row vector
Element tapering, specified as a complex-valued scalar or a complex-valued 1-by-N row vector. In this vector, N represents the number of elements in the array.
Also known as element weights, tapers multiply the array element responses. Tapers modify both amplitude and phase of the response to reduce side lobes or steer the main response axis.
If Taper is a scalar, the same weight is applied to each element. If Taper is a vector, a weight from the vector is applied to the corresponding sensor element. The number of weights must match the number of elements of the array.
When you set Specify sensor array as to Replicated
subarray
, this parameter applies to each subarray.
Subarray definition matrix — Define elements belonging to subarrays
logical matrix
Specify the subarray selection as an M-by-N matrix. M is the number of subarrays and N is the total number of elements in the array. Each row of the matrix represents a subarray and each entry in the row indicates when an element belongs to the subarray. When the entry is zero, the element does not belong the subarray. A nonzero entry represents a complex-valued weight applied to the corresponding element. Each row must contain at least one nonzero entry.
The phase center of each subarray lies at the subarray geometric center. The subarray geometric center depends on the Subarray definition matrix and Geometry parameters.
Dependencies
To enable this parameter, set Specify sensor array as to
Partitioned array
.
Subarray steering method — Specify subarray steering method
None
(default) | Phase
| Time
Subarray steering method, specified as one of
None
Phase
Time
Custom
Selecting Phase
or Time
opens the
Steer
input port on the Narrowband Receive Array,
Narrowband Transmit Array, Wideband Receive Array,
Wideband Transmit Array blocks, Constant Gamma
Clutter, and GPU Constant Gamma Clutter blocks.
Selecting Custom
opens the WS
input port on the
Narrowband Receive Array, Narrowband Transmit Array,
Wideband Receive Array, Wideband Transmit Array
blocks, Constant Gamma Clutter, and GPU Constant Gamma
Clutter blocks.
Dependencies
To enable this parameter, set Specify sensor array as to
Partitioned array
or Replicated
subarray
.
Phase shifter frequency (Hz) — Subarray phase shifting frequency
3.0e8
(default) | positive real-valued scalar
Operating frequency of subarray steering phase shifters, specified as a positive real-valued scalar. Units are Hz.
Dependencies
To enable this parameter, set Sensor array to Partitioned
array
or Replicated subarray
and set Subarray
steering method to Phase
.
Number of bits in phase shifters — Subarray steering phase shift quantization bits
0
(default) | non-negative integer
Subarray steering phase shift quantization bits, specified as a non-negative integer. A value of zero indicates that no quantization is performed.
Dependencies
To enable this parameter, set Sensor array to Partitioned
array
or Replicated subarray
and set Subarray
steering method to Phase
.
Subarrays layout — Subarray position specification
Rectangular
(default) | Custom
Specify the layout of replicated subarrays as Rectangular
or Custom
.
When you set this parameter to
Rectangular
, use the Grid size and Grid spacing parameters to place the subarrays.When you set this parameter to
Custom
, use the Subarray positions (m) and Subarray normals parameters to place the subarrays.
Dependencies
To enable this parameter, set Sensor array to Replicated
subarray
Grid size — Dimensions of rectangular subarray grid
[1,2]
(default)
Rectangular subarray grid size, specified as a single positive integer, or a 1-by-2 row vector of positive integers.
If Grid size is an integer scalar, the
array has an equal number of subarrays in each row and column. If Grid
size is a 1-by-2 vector of the form [NumberOfRows,
NumberOfColumns]
, the first entry is the number of subarrays
along each column. The second entry is the number of subarrays in
each row. A row is along the local y-axis, and
a column is along the local z-axis. The figure
here shows how you can replicate a 3-by-2 URA subarray using a Grid
size of [1,2]
.
Dependencies
To enable this parameter, set Sensor array to Replicated
subarray
and Subarrays layout to Rectangular
.
Grid spacing (m) — Spacing between subarrays on rectangular grid
Auto
(default) | positive real-valued scalar | 1-by-2 vector of positive real-values
The rectangular grid spacing of subarrays, specified as a positive,
real-valued scalar, a 1-by-2 row vector of positive, real-values,
or Auto
. Units are in meters.
If Grid spacing is a scalar, the spacing along the row and the spacing along the column is the same.
If Grid spacing is a 1-by-2 row vector, the vector has the form
[SpacingBetweenRows,SpacingBetweenColumn]
. The first entry specifies the spacing between rows along a column. The second entry specifies the spacing between columns along a row.If Grid spacing is set to
Auto
, replication preserves the element spacing of the subarray for both rows and columns while building the full array. This option is available only when you specify Geometry asULA
orURA
.
Dependencies
To enable this parameter, set Sensor array to Replicated
subarray
and Subarrays layout to Rectangular
.
Subarray positions (m) — Positions of subarrays
[0,0;0.5,0.5;0,0]
(default) | 3-by-N real-valued matrix
Positions of the subarrays in the custom grid, specified as
a real 3-by-N matrix, where N is
the number of subarrays in the array. Each column of the matrix represents
the position of a single subarray in the array local coordinate system.
The coordinates are expressed in the form [x; y; z]
.
Units are in meters.
Dependencies
To enable this parameter, set Sensor array to Replicated
subarray
and Subarrays layout to Custom
.
Subarray normals — Direction of subarray normal vectors
[0,0;0,0]
(default) | 2-by-N real matrix
Specify the normal directions of the subarrays in the array.
This parameter value is a 2-by-N matrix, where N is
the number of subarrays in the array. Each column of the matrix specifies
the normal direction of the corresponding subarray, in the form [azimuth;elevation]
.
Angle units are in degrees. Angles are defined with respect to the
local coordinate system.
You can use the Subarray positions and Subarray normals parameters to represent any arrangement in which pairs of subarrays differ by certain transformations. The transformations can combine translation, azimuth rotation, and elevation rotation. However, you cannot use transformations that require rotation about the normal.
Dependencies
To enable this parameter, set the Sensor array parameter
to Replicated subarray
and the Subarrays
layout to Custom
.
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.
Version History
Introduced in R2021a
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