phased.RadarTarget
Radar target
Description
The RadarTarget
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 crosssection (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 nonpolarized processing, the radar cross section is encapsulated
in a single scalar quantity called the MeanRCS
. For polarized processing,
specify the radar crosssection as a 2by2 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 SeedSource
and Seed
properties control the random fluctuations.
The properties that you can use to model the radar crosssection or scattering matrix depend upon the polarization type.
EnablePolarization Value  Use These Properties 

false 

true 

To compute the signal reflected from a radar target:
Define and set up your radar target. See Construction.
Call
step
to compute the reflected signal according to the properties ofphased.RadarTarget
. The behavior ofstep
is specific to each object in the toolbox.
Note
Starting in R2016b, instead of using the step
method
to perform the operation defined by the System object, you can
call the object with arguments, as if it were a function. For example, y
= step(obj,x)
and y = obj(x)
perform
equivalent operations.
Construction
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, Name
,Value
)H
, with each specified
property set to the specified value. You can specify additional namevalue
pair arguments in any order as (Name1
,Value1
,...,NameN
,ValueN
).
Properties

Allow polarized signals Set this property to Default:  

Target scattering mode Target scattering mode specified as one of Default:  

Sources of mean scattering matrix of target Source of mean scattering matrix of target specified as one of
Default:  

Mean radar scattering matrix for polarized signal Mean radar scattering matrix specified as a complex–valued 2by2 matrix. This matrix
represents the mean value of the target's radar crosssection. Units are in square meters. The
matrix has the form Default:  

Source of mean radar cross section Specify whether the mean RCS value of the target comes from the
When Default:  

Mean radar cross section Specify the mean value of the target's radar cross section as a nonnegative scalar or as
a 1byM realvalued, 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
When Default:  

Target statistical model Specify the statistical model of the target as one of
Default:  

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. Default:  

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
Default:  

Seed for random number generator Specify the seed for the random number generator as a scalar
integer between 0 and 2^{32}–1. This
property applies when you set the Default: 
Methods
reset  Reset states of radar target object 
step  Reflect incoming signal 
Common to All System Objects  

release  Allow System object property value changes 
Examples
Algorithms
For a narrowband nonpolarized signal, the reflected signal, Y, is
$$Y=\sqrt{G}\cdot X,$$
where:
X is the incoming signal.
G is the target gain factor, a dimensionless quantity given by
$$G=\frac{4\pi \sigma}{{\lambda}^{2}}.$$
σ is the mean radar crosssection (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, (E_{H}, E_{V}), with horizontal and vertical components. The scattering matrix, S, replaces the scalar crosssection, σ. Through the scattering matrix, the incident horizontal and vertical polarized signals are converted into the reflected horizontal and vertical polarized signals.
$$\left[\begin{array}{c}{E}_{H}^{(scat)}\\ {E}_{V}^{(scat)}\end{array}\right]=\sqrt{\frac{4\pi}{{\lambda}^{2}}}\left[\begin{array}{cc}{S}_{HH}& {S}_{VH}\\ {S}_{HV}& {S}_{VV}\end{array}\right]\left[\begin{array}{c}{E}_{H}^{(inc)}\\ {E}_{V}^{(inc)}\end{array}\right]=\sqrt{\frac{4\pi}{{\lambda}^{2}}}\left[S\right]\left[\begin{array}{c}{E}_{H}^{(inc)}\\ {E}_{V}^{(inc)}\end{array}\right]$$
References
[1] Mott, H., Antennas for Radar and Communications, John Wiley & Sons, 1992.
[2] Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGrawHill, 2005.
[3] Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGrawHill, 2001.
Extended Capabilities
Version History
Introduced in R2011a
See Also
phased.FreeSpace
 phased.Platform
 phased.BackscatterRadarTarget
 phased.BackscatterSonarTarget
 phased.WidebandBackscatterRadarTarget
 backscatterPedestrian
(Radar Toolbox)