Radar target
The RadarTarget
System
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 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, you should
specify the EnablePolarization
property as false
.
To utilize polarization, you must 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, the radar crosssection is more generally
expressed by a 2by2 scattering matrix in the ScatteringMatrix
property.
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 Model
property.
The random fluctuations are controlled by the SeedSource
and Seed
properties.
The properties that you can use to model the radar crosssection or scattering matrix depend upon the polarization type.
EnablePolarization  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 of phased.RadarTarget
.
The behavior of step
is specific to each object in
the toolbox.
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.
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
).

Allow polarized signals Set this property to Default:  

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

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

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

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

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 1byM 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 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: 
reset  Reset states of radar target object 
step  Reflect incoming signal 
Common to All System Objects  

clone  Create System object with same property values 
getNumInputs  Expected number of inputs to a System object 
getNumOutputs  Expected number of outputs of a System object 
isLocked  Check locked states of a System object (logical) 
release  Allow System object property value changes 
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.
$$\left[\begin{array}{c}{E}_{H}^{(scat)}\\ {E}_{V}^{(scat)}\end{array}\right]=\sqrt{\frac{4\pi}{{\lambda}^{2}}}\left[\begin{array}{cc}{S}_{HH}& {S}_{VH}\\ {S}_{HV}& {S}_{VV}\end{array}\right]\left[\begin{array}{c}{E}_{H}^{(inc)}\\ {E}_{V}^{(inc)}\end{array}\right]=\sqrt{\frac{4\pi}{{\lambda}^{2}}}\left[S\right]\left[\begin{array}{c}{E}_{H}^{(inc)}\\ {E}_{V}^{(inc)}\end{array}\right]$$
[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.