Backscatter wideband signals from radar target
Phased Array System Toolbox / Environment and Target
The Wideband Backscatter Radar Target block models the monostatic reflection of nonpolarized wideband electromagnetic signals from a radar target. The target radar cross-section (RCS) model includes all four Swerling target fluctuation models and a nonfluctuating model. You can model several targets simultaneously by specifying multiple RCS matrices.
X— Wideband incident nonpolarized signal
Wideband incident nonpolarized signal, specified as an N-by-M complex-valued matrix. The quantity N is the number of signal samples, and M is the number of independent signals reflecting off the target. Each column contains an independent signal to be reflected from the target.
The size of the first dimension of this input matrix can vary to simulate a changing signal length, such as a pulse waveform with variable pulse repetition frequency.
Complex Number Support: Yes
Ang— Incident signal direction
Incident signal direction, specified as a 2-by-1 or 2-by-M real-valued
column matrix of positive values. Each column of
the incident direction of the corresponding signal. The number of
Ang must match the number of independent
X. The columns take the form
Units are in degrees.
Update— Enable update of RCS
Option to enable updating of RCS values for fluctuation models,
true, a new
RCS value is generated each time you run the block. If
the RCS remains unchanged.
To enable this port, set the Fluctuation model parameter to one of the Swerling models.
Out— Wideband reflected nonpolarized signal
Wideband reflected nonpolarized signal, returned as an N-by-M complex-valued matrix. The quantity N is the number of signal samples, and M is the number of independent signals reflected from the target. Each column contains an independent signal reflected from the target.
Backscatter pattern frequency vector (Hz)— Wideband backscatter pattern frequencies
[0,1e20](default) | real-valued row vector of positive values in strictly increasing order
Specify the frequencies used in the RCS matrix. The elements of this vector must be in strictly increasing order. The target has no response outside this frequency range. Frequency units are in hertz.
Azimuth angles (deg)— Azimuth angles
[-180:180](default) | 1-by-P real-valued row vector | P-by-1 real-valued column vector
Azimuth angles used to define the angular coordinates of each column of the matrices specified by the RCS pattern (m^2) parameter. Specify the azimuth angles as a length P vector. P must be greater than two. Angle units are in degrees.
Elevation angles (deg)— Elevation angles
[-90:90](default) | 1-by-Q real-valued row vector | Q-by-1 real-valued column vector
Elevation angles used to define the angular coordinates of each row of the matrices specified by the RCS pattern (m^2) parameter. Specify the elevation angles as a length Q vector. Q must be greater than two. Angle units are in degrees.
RCS pattern (m^2)— Radar cross-section pattern
ones(181,361)(default) | Q-by-P complex-valued matrix | Q-by-P-by-K complex-valued array | 1-by-P-by-K complex-valued array | K-by-P complex-valued matrix
Radar cross-section pattern, specified as a complex-valued matrix or array.
|Q-by-P matrix||Specifies a matrix of RCS values as a function of Q elevation angles and P azimuth angles. The same RCS matrix is used for all frequencies.|
|Q-by-P-by-K array||Specifies an array of RCS patterns as a function of Q elevation angles, P azimuth angles, and K frequencies. If K = 1, the RCS pattern is equivalent to a Q-by-P matrix.|
|1-by-P-by-K array||Specifies a matrix of RCS values as a function of P azimuth angles and K frequencies. These dimension formats apply when there is only one elevation angle.|
Q is the length of the vector specified by the Elevation angles (deg) parameter.
P is the length of the vector specified by the Azimuth angles (deg) parameter.
K is the number of frequencies specified by the Backscatter pattern frequency vector (Hz) parameter.
You can specify patterns for L targets by putting L patterns into a cell array. All patterns must have the same dimensions. The value of L must match the column dimensions of the signals passed as input into the block. You can, however, use one pattern to model L multiple targets.
RCS units are in square meters.
Complex Number Support: Yes
Fluctuation model— Target fluctuation model
Target fluctuation model, specified as
Swerling4. If you set this parameter
to a value other than
must pass either
Propagation speed (m/s)— Signal propagation speed
Signal propagation speed, specified as a real-valued positive
scalar. The default value of the speed of light is the value return
Operating frequency (Hz)— Signal carrier frequency
300.0e6(default) | positive real-valued scalar
Signal carrier frequency, specified as a positive real-valued scalar. Units are in hertz.
Number of subbands— Number of processing subbands
64(default) | positive integer
Number of processing subbands, specified as a positive integer.