Backscatter Radar Target
Backscatter radar target
Libraries:
Phased Array System Toolbox /
Environment and Target
Description
The Backscatter Radar Target block models the monostatic radar reflections of nonpolarized electromagnetic signals from a target. Target model includes all four Swerling target fluctuation models and non-fluctuating model. You can model several targets simultaneously by specifying multiple radar cross-section (RCS) matrices.
Ports
Input
X — Narrowband signal
N-by-1 complex-valued
vector | N-by-M complex-valued
matrix
Narrowband nonpolarized signal, specified as an N-by-1 complex-valued vector or an N-by-M complex-valued matrix. The quantity N is the number of signal samples and M is the number of signals reflecting from the target. Each column corresponds to an independent signal incident at a different reflecting angle.
The size of the first dimension of the input matrix can vary to simulate a changing signal length. A size change can occur, for example, in the case of a pulse waveform with variable pulse repetition frequency.
Data Types: double
Ang — Incident signal direction
2-by-1 real-valued column vector | 2-by-M real-valued column matrix
Incident signal direction, specified as a 2-by-1 real-valued column vector or a
2-by-M real-valued column matrix.
M is the number of signals reflecting from the
target. Each column of Ang
specifies the incident
direction of the corresponding signal in the form of an
[AzimuthAngle;ElevationAngle]
pair. Units are
degrees. The number of columns in Ang
must match
the number of independent signals in X
.
Example: [30;45]
Data Types: double
Update — Switch to update RCS
false
| true
Switch to update RCS fluctuation model values, specified as
false
or true
. When
Update
is true
, the RCS
value is updated. If Update
is
false
, the RCS remains unchanged.
Dependencies
To enable this port, set the Fluctuation
model drop-down menu to
Swerling1
,
Swerling2
,
Swerling3
, or
Swerling4
.
Output
Port_1 — Narrowband reflected signal
1-by-M complex-valued vector | N-by-M complex-valued
matrix
Narrowband nonpolarized signal, specified as an 1-by-M complex-valued vector or a N-by-M complex-valued matrix. Each column contains an independent signal reflected from the target.
The quantity N is the number of signal samples and M is the number of signals reflecting off the target. Each column corresponds to a different reflecting angle.
The output port contains signal samples arriving at the signal destination within the current input time frame. When the propagation time from source to destination exceeds the current time frame duration, the output does not contain all contributions from the input of the current time frame.
Parameters
Azimuth angles (deg) — Azimuth angles
[-180:180]
(default) | 1-by-P real-valued row vector | P-by-1 real-valued column vector
Specify the azimuth angles used to define the angular coordinates of the RCS pattern (m^2) parameter. Specify azimuth angles as a length P vector. Units are degrees. P must be greater than two. This parameter determines the incident azimuthal arrival angle of any element of the cross-section patterns.
Data Types: double
Elevation angles (deg) — Elevation angles
[-90:90]
(default) | 1-by-Q real-valued row vector | Q-by-1 real-valued column vector
Specify the elevation angles used to define the angular coordinates of the RCS pattern (m^2) parameter. Specify elevation angles as a length Q vector. Units are degrees. Q must be greater than two. This parameter determines the incident elevation arrival angle of any element of the cross-section patterns.
RCS pattern (m^2) — Radar cross-section pattern
ones(181,361)
(default) | Q-by-P real-valued matrix | Q-by-P-by-M
real-valued array | 1-by-P real-valued vector | M-by-P real-valued matrix
Radar cross-section pattern, specified as a Q-by-P real-valued matrix or a Q-by-P-by-M real-valued array.
Q is the length of the vector in the Elevation angles (deg) parameter.
P is the length of the vector in the Azimuth angles (deg) parameter.
M is the number of target patterns. The number of patterns corresponds to the number of signals passed into the input port
X
. You can, however, use a single pattern to model multiple signals reflecting from a single target.
You can, however, use a single pattern to model multiple signals reflecting from a single target. Pattern units are square-meters.
Pattern units are square-meters.
Fluctuation model — Target fluctuation model
Nonfluctuating
(default) | Swerling1
| Swerling2
| Swerling3
| Swerling4
Specify the statistical model of the target as either
Nonfluctuating
,
Swerling1
,
Swerling2
,
Swerling3
, or
Swerling4
. When you set this parameter to a
value other than Nonfluctuating
, you then set
radar cross-sections parameters using the Update
input
port.
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
Operating frequency (Hz) — Operating frequency
3e8
(default) | positive scalar
Carrier frequency of the signal that reflects from the target, specified as a positive scalar. Units are in hertz.
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).
Programmatic Use
Block
Parameter:SimulateUsing |
Type:enum |
Values:Interpreted
Execution , Code Generation |
Default:Interpreted
Execution |
Version History
Introduced in R2016a
See Also
MATLAB Command
You clicked a link that corresponds to this MATLAB command:
Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)