System object™ models how a signal is reflected from a radar target. The quantity that determines
the response of a target to incoming signals is called the radar target cross-section (RCS).
While all electromagnetic radar signals are polarized, you can sometimes ignore polarization and
process them as if they were scalar signals. To ignore polarization, specify the
EnablePolarization property as
false. To utilize
polarization, specify the
EnablePolarization property as
true. For non-polarized processing, the radar cross section is encapsulated
in a single scalar quantity called the
MeanRCS. For polarized processing,
specify the radar cross-section as a 2-by-2 scattering matrix in the
ScatteringMatrix property. For both polarization processing types, there
are several Swerling models available that can generate random fluctuations in the RCS. Choose
these models using the
Model property. The
Seed properties control the random fluctuations.
The properties that you can use to model the radar cross-section or scattering matrix depend upon the polarization type.
|EnablePolarization Value||Use These Properties|
To compute the signal reflected from a radar target:
Define and set up your radar target. See Construction.
stepto compute the reflected signal according to the properties of
phased.RadarTarget. The behavior of
stepis specific to each object in the toolbox.
Starting in R2016b, instead of using the
to perform the operation defined by the System object, you can
call the object with arguments, as if it were a function. For example,
= step(obj,x) and
y = obj(x) perform
H = phased.RadarTarget creates a radar
target System object,
H, that computes the
reflected signal from a target.
H = phased.RadarTarget( creates
a radar target object,
H, with each specified
property set to the specified value. You can specify additional name-value
pair arguments in any order as (
Allow polarized signals
Set this property to
Target scattering mode
Target scattering mode specified as one of
Sources of mean scattering matrix of target
Source of mean scattering matrix of target specified as one of
Mean radar scattering matrix for polarized signal
Mean radar scattering matrix specified as a complex–valued 2-by-2 matrix. This matrix
represents the mean value of the target's radar cross-section. Units are in square meters. The
matrix has the form
Source of mean radar cross section
Specify whether the mean RCS value of the target comes from the
Mean radar cross section
Specify the mean value of the target's radar cross section as a nonnegative scalar or as
a 1-by-M real-valued, nonnegative row vector. Units are in square meters.
Using a vector lets you simultaneously process multiple targets. The quantity
M is the number of targets. This property is used when
Target statistical model
Specify the statistical model of the target as one of
Signal propagation speed
Specify the propagation speed of the signal, in meters per second, as a positive scalar.
Default: Speed of light
Signal carrier frequency
Specify the carrier frequency of the signal you are reflecting from the target, as a scalar in hertz.
Source of seed for random number generator
Specify how the object generates random numbers. Values of this property are:
The random numbers are used to model random RCS values. This property applies when the
Seed for random number generator
Specify the seed for the random number generator as a scalar
integer between 0 and 232–1. This
property applies when you set the
|reset||Reset states of radar target object|
|step||Reflect incoming signal|
|Common to All System Objects|
Allow System object property value changes
Compute Reflected Signal from a Non-fluctuating Radar Target
Create a simple signal and compute the value of the reflected signal from a target having a radar cross section of . Set the radar cross section using the
MeanRCS property. Set the radar operating frequency to 600 MHz.
x = ones(10,1); target = phased.RadarTarget('Model','Nonfluctuating',... 'MeanRCS',10,... 'OperatingFrequency',600e6); y = target(x); disp(y(1:3))
22.4355 22.4355 22.4355
This value agrees with the formula where
For a narrowband nonpolarized signal, the reflected signal, Y, is
X is the incoming signal.
G is the target gain factor, a dimensionless quantity given by
σ is the mean radar cross-section (RCS) of the target.
λ is the wavelength of the incoming signal.
The incident signal on the target is scaled by the square root of the gain factor.
For narrowband polarized waves, the single scalar signal, X, is replaced by a vector signal, (EH, EV), with horizontal and vertical components. The scattering matrix, S, replaces the scalar cross-section, σ. Through the scattering matrix, the incident horizontal and vertical polarized signals are converted into the reflected horizontal and vertical polarized signals.
 Mott, H., Antennas for Radar and Communications, John Wiley & Sons, 1992.
 Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.
 Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Usage notes and limitations:
See System Objects in MATLAB Code Generation (MATLAB Coder).
Introduced in R2011a
backscatterPedestrian (Radar Toolbox)