object™ models how
a signal is reflected from a radar target. The quantity that determines
the response of a target to an 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, you should
EnablePolarization property as
To utilize polarization, you must specify the
true. For non-polarized processing, the radar
cross section is encapsulated in a single scalar quantity called the
For polarized processing, the radar cross-section is more generally
expressed by a 2-by-2 scattering matrix in the
For both polarization processing types, there are several Swerling
models available to be used to generate random fluctuations in the
RCS. These models are chosen using the
The random fluctuations are controlled by the
The properties that you can use to model the radar cross-section or scattering matrix depend upon the polarization type.
|Use these properties|
To compute the signal reflected from a radar target:
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
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
Source of target mean scattering matrix
Source of target mean scattering matrix specified as one of
Mean radar scattering matrix
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 (in square meters). The matrix has the form
Source of mean radar cross section
Specify whether the target’s mean RCS value(s) comes
Mean radar cross section
Specify the mean value of the target's radar cross section (in
square meters) as a nonnegative scalar or as a 1-by-M nonnegative
row vector. Using
a vector allows you to process multiple targets simultaneous. The
quantity Mis 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|
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); sRadarTarget = phased.RadarTarget('Model','Nonfluctuating',... 'MeanRCS',10,... 'OperatingFrequency',600e6); y = step(sRadarTarget,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.
Usage notes and limitations:
See System Objects in MATLAB Code Generation (MATLAB Coder).