System object: phased.STAPSMIBeamformer
Perform SMI STAP processing on input data
Y = step(H,X,CUTIDX)
Y = step(H,X,CUTIDX,PRF)
Y = step(H,X,CUTIDX,ANG)
Y = step(H,X,CUTIDX,DOP)
[Y,W] = step(___)
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
Y = step(H,X,CUTIDX) applies SMI processing to the input data,
X must be a 3-dimensional
M-by-N-by-P numeric array
whose dimensions are (range, channels, pulses). The processing weights are calculated
according to the range cell specified by
CUTIDX. The targeting
direction and the targeting Doppler are specified by
Doppler properties, respectively.
Y is a
column vector of length M. This syntax is available when the
DirectionSource property is
DopplerSource property is
The size of the first dimension of the input matrix can vary to simulate a changing signal length. A size change can occur, for example, in the case of a pulse waveform with variable pulse repetition frequency.
Y = step(H,X,CUTIDX,PRF) uses
PRF as the
pulse repetition frequency. This syntax is available when the
PRFSource property is
Y = step(H,X,CUTIDX,ANG) uses
the targeting direction. This syntax is available when the
be a 2-by-1 vector in the form of
[AzimuthAngle; ElevationAngle] (in
degrees). The azimuth angle must be between –180 and 180. The
elevation angle must be between –90 and 90.
Y = step(H,X,CUTIDX,DOP) uses
the targeting Doppler frequency (in hertz). This syntax is available
DopplerSource property is
DOP must be a scalar.
You can combine optional input arguments when their enabling
properties are set:
Y = step(H,X,CUTIDX,ANG,DOP)
[Y,W] = step(___) returns the additional output,
W, as the processing weights. This syntax is available when the
WeightsOutputPort property is
W is a column vector of length
The object performs an initialization the first time the object is executed. This
initialization locks nontunable properties
and input specifications, such as dimensions, complexity, and data type of the input data.
If you change a nontunable property or an input specification, the System object issues an error. To change nontunable properties or inputs, you must first
release method to unlock the object.
Process Data Cube Using SMI
Process a data cube using an SMI beamformer. The weights are calculated for the 71st cell of a collected data cube pointing in the azimuth and elevation direction (45°,-35°) and with a Doppler of 12.980 kHz.
Load the cube data and create the SMI beamformer.
load STAPExampleData; beamformer = phased.STAPSMIBeamformer('SensorArray',STAPEx_HArray, ... 'PRF',STAPEx_PRF,'PropagationSpeed',STAPEx_PropagationSpeed, ... 'OperatingFrequency',STAPEx_OperatingFrequency, ... 'NumTrainingCells',100,'WeightsOutputPort',true, ... 'DirectionSource','Input port','DopplerSource','Input port'); [y,w] = beamformer(STAPEx_ReceivePulse,71,[45;-35],12.980e3);
Plot the angle-doppler response.
response = phased.AngleDopplerResponse( ... 'SensorArray',beamformer.SensorArray, ... 'OperatingFrequency',beamformer.OperatingFrequency, ... 'PRF',beamformer.PRF,'PropagationSpeed',beamformer.PropagationSpeed); plotResponse(response,w)