EngeePhased.RadarTarget
Radar target.
| Library |
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| Block |
Description
An object EngeePhased.RadarTarget simulates the reflection of a signal from a radar target. The value that determines the target’s response to incoming signals is called the effective scattering area (ESR).
To simulate the signal reflected from the target, follow these steps:
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Create an object EngeePhased.RadarTarget and set its properties.
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Call the object with arguments as if it were a function.
To learn more about how to work with system objects, see Engee System Objects.
Syntax
Creation
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target = EngeePhased.RadarTarget()— creates a radar target object with default property values. -
target = EngeePhased.RadarTarget(Name=Value)— creates a radar target object with the specified properties as a pairName=Value, whereName— the name of the property, andValue— the appropriate value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their default values.
Using
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Y = target(X)— returns the reflected signal Y caused by the incident signal X. Use this syntax if for the property Model the value is set"Nonfluctuating". In this case, the value of the property [Property is used as the EPR value.:MeanRCS]. If specified for incident signals, you can set the EPR as a scalar or vector on . For a scalar, the same value will be applied to all signals. -
Y = target(X,MEANRCS)— uses MEANRCS as the average EPR value. This syntax is available if for the property MeanRCSSource value set"Input port", and for Model the value is set"Nonfluctuating". -
Y = target(X,UPDATERCS)— uses UPDATERCS as an indicator for updating the EPR value. This syntax is available if for the property Model the value is set"Swerling1","Swerling2","Swerling3"or"Swerling4". In this case, the value of the property [Property is used as the EPR value.:MeanRCS]. -
Y = target(X,MEANRCS,UPDATERCS)— simultaneously uses MEANRCS and UPDATERCS. This syntax is available if for the property MeanRCSSource value set"Input port", and for the property Model the value is set"Swerling1","Swerling2","Swerling3"or"Swerling4". For this syntax, changes to MEANRCS will be ignored after the first call to the object function.
Arguments
Input arguments
X — falling signal
+
The complex column vector is N by 1 | the complex matrix of N by M
Details
The incident signal, defined as a complex column vector on or the matrix on , where — the number of signals, each of which corresponds to a separate goal, and — the number of samples in each signal.
The size of the first dimension of the input matrix can be varied to simulate a changing signal length. A change in size may occur, for example, in the case of a pulse signal with a variable pulse repetition rate.
| Типы данных |
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| Support for complex numbers |
Yes |
MEANRCS — the average value of the EPR
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scalar | vector-row 1 by M
Details
The average EPR value, set as a non-negative scalar or a string vector on for multiple purposes.
Dependencies
To use this argument, set for MeanRCSSource value "Input port".
| Типы данных |
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UPDATERCS — EPR update
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false | true
Details
Resolution of updating EPR values for fluctuation models.
If UPDATERCS is set to true, a new EPR value is generated.
If UPDATERCS is set to false, the previous EPR value is used.
Dependencies
To use this argument, set for Model value "Swerling1", "Swerling2", "Swerling3" or "Swerling4".
| Типы данных |
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Features
#
MeanRCS —
average EPR value
Scalar / array of real numbers
Details
The average value of the EPR in m2, given as a non-negative scalar or row vector on , where — number of targets.
By default — 1.
Dependencies
To use this property, set for MeanRCSSource value "Property".
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PropagationSpeed —
signal propagation speed
Real number
Details
The propagation velocity of the signal in m/s, given as a positive scalar. The speed of light is used By default 299792458.
#
OperatingFrequency —
Operating frequency
Real number
Details
The operating frequency in Hz, set as a positive scalar.
By default — 3e8.
#
Model —
target fluctuation model
String
Details
The target fluctuation model, given as "Nonfluctuating" (By default), "Swerling1", "Swerling2", "Swerling3" or "Swerling4".
If you set this property to a value other than "Nonfluctuating", use the input argument UPDATERCS when calling the function.
Examples
Calculation of the reflected signal from a non-oscillating radar target
Details
Let’s create a simple signal and calculate the value of the reflected signal from a target with a radar cross-section. 10 m2. Setting the EPR using the MeanRCS. Set the operating frequency of the radar to 600 MHz.
using EngeePhased
x = ones(10,1)
target = EngeePhased.RadarTarget(Model="Nonfluctuating",MeanRCS=10,OperatingFrequency=600e6)
y = target(x)10×1 Matrix{ComplexF64}:
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0im
22.43548588429638 + 0.0imThe resulting value corresponds to the result of the calculation using the formula , where .
Algorithms
Details
For a narrow-band unpolarized signal, the reflected signal equal to:
where
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— input signal;
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— target gain factor, a dimensionless value defined as follows:
where
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— effective scattering area (ESR) of the target;
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— the wavelength of the input signal.
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The signal incident on the target is scaled by the square root of the gain factor.