phased.AngleDopplerResponse

Angle-Doppler response

Description

The AngleDopplerResponse object calculates the angle-Doppler response of input data.

To compute the angle-Doppler response:

Define and set up your angle-Doppler response calculator. See Construction.
Call step to compute the angle-Doppler response of the input signal according to the properties of phased.AngleDopplerResponse. The behavior of step 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.AngleDopplerResponse creates an angle-Doppler response System object, H. This object calculates the angle-Doppler response of the input data.

H = phased.AngleDopplerResponse(Name,Value) creates angle-Doppler object, H, with each specified property Name set to the specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

Properties

SensorArray

Sensor array

Sensor array specified as an array System object belonging to the phased package. A sensor array can contain subarrays.

Default: phased.ULA with default property values

PropagationSpeed

Signal propagation speed

Specify the propagation speed of the signal, in meters per second, as a positive scalar. You can specify this property as single or double precision.

Default: Speed of light

OperatingFrequency

System operating frequency

Specify the operating frequency of the system in hertz as a positive scalar. The default value corresponds to 300 MHz. You can specify this property as single or double precision.

Default: 3e8

PRFSource

Source of PRF values

Source of the PRF values for the STAP processor, specified as 'Property' or 'Input port'. When you set this property to 'Property', the PRF is determined by the value of the PRF property. When you set this property to 'Input port', the PRF is determined by an input argument to the step method at execution time.

Default: 'Property'

PRF

Pulse repetition frequency

Specify the pulse repetition frequency (PRF) in hertz of the input signal as a positive scalar. This property applies when you set the PRFSource property to 'Property'. You can specify this property as single or double precision.

Default: 1

ElevationAngleSource

Source of elevation angle

Specify whether the elevation angle comes from the ElevationAngle property of this object or from an input argument in step. Values of this property are:

`'Property'`	The `ElevationAngle` property of this object specifies the elevation angle.
`'Input port'`	An input argument in each invocation of `step` specifies the elevation angle.

Default: 'Property'

ElevationAngle

Elevation angle

Specify the elevation angle in degrees used to calculate the angle-Doppler response as a scalar. The angle must be between –90 and 90. This property applies when you set the ElevationAngleSource property to 'Property'. You can specify this property as single or double precision.

Default: 0

NumAngleSamples

Number of samples in angular domain

Specify the number of samples in the angular domain used to calculate the angle-Doppler response as a positive integer. This value must be greater than 2. You can specify this property as single or double precision.

Default: 256

NumDopplerSamples

Number of samples in Doppler domain

Specify the number of samples in the Doppler domain used to calculate the angle-Doppler response as a positive integer. This value must be greater than 2. You can specify this property as single or double precision.

Default: 256

Methods

plotResponse	Plot angle-Doppler response
step	Calculate angle-Doppler response

Common to All System Objects
`release`	Allow System object property value changes

Examples

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Calculate Angle-Doppler Response

Open Live Script

Calculate the angle-Doppler response of the 190th cell of a collected data cube.

Load data cube and construct a phased.AngleDopplerResponse System object™.

load STAPExampleData;
x = shiftdim(STAPEx_ReceivePulse(190,:,:));
response = phased.AngleDopplerResponse(...
    'SensorArray',STAPEx_HArray,...
    'OperatingFrequency',STAPEx_OperatingFrequency,...
    'PropagationSpeed',STAPEx_PropagationSpeed,...
    'PRF',STAPEx_PRF);

Plot angle-Doppler response.

[resp,ang_grid,dop_grid] = response(x);
contour(ang_grid,dop_grid,abs(resp))
xlabel('Angle')
ylabel('Doppler')

Figure contains an axes object. The axes object with xlabel Angle, ylabel Doppler contains an object of type contour.

Algorithms

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Response Computation

phased.AngleDopplerResponse generates the response using a conventional beamformer and an FFT-based Doppler filter. For further details, see [1].

Single Precision

This System object supports single and double precision for input data, properties, and arguments. If the input data X is single precision, the output data is single precision. If the input data X is double precision, the output data is double precision. The precision of the output is independent of the precision of the properties and other arguments.

References

[1] Guerci, J. R. Space-Time Adaptive Processing for Radar. Boston: Artech House, 2003.

Extended Capabilities

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).

Version History

Introduced in R2011a