Wideband Backscatter Radar Target
Broadband radar target backscatter signals.
Description
The Wideband Backscatter Radar Target block models the monostatic reflection of unpolarised broadband electromagnetic signals from a radar target. The effective scattering surface (ESR) model includes four Swerling target fluctuation models and one non-fluctuating model. Multiple targets can be modelled simultaneously by specifying multiple effective scattering surface (ESR) matrices.
Ports
Input
X - broadband incident unpolarised signal
complex vector-column N by 1 | complex matrix N by M
A broadband incident unpolarised signal in the form of a complex vector-column N by 1 or a complex matrix N by M. The value M is the number of independent signals reflected from the target. The value N is the number of samples in each signal. Each column contains an independent signal reflected from the target.
The size of the first dimension of the input matrix can be varied to model the varying signal length. The size variation can occur, for example, in the case of a pulsed signal with a variable pulse repetition rate.
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Support for complex numbers: Yes
Ang is the direction of the incident signal.
real vector-column 2 by 1 | real matrix 2 by M
The direction of the incident signal given as a real vector-column 2 by 1 or a real matrix 2 by M. The value M is the number of signals reflected from the target. Each Ang column specifies the direction of incidence of the corresponding signal as a pair of angles [AzimuthAngle;ElevationAngle]. The units of measurement are degrees. The number of columns in Ang must correspond to the number of independent signals in X.
*Example: [30;45]
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Update - radar cross section update indicator
false | true
Toggles to update the fluctuation model effective scattering surface (EDS) values set as false or true. If the value on the Update port is true, the EDS value is updated. If the value on the Update port is false, the EDS value remains unchanged.
Dependencies
To use this port, set the Fluctuation model parameters to any value other than Nonfluctuating.
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Output
Out - wideband reflected signal
complex vector-column 1 on M | complex matrix N on M
A broadband unpolarised signal in the form of a complex vector 1 on M or a complex matrix N on M. Each column contains an independent signal reflected from the target. The dimensionality of the output signal is equal to the dimensionality of the input signal.
The quantity N is the number of signal samples and M is the number of signals reflected from the target. Each column corresponds to a different reflection angle.
The output port contains the signal samples that arrived at the signal destination during the current input time interval. If the signal propagation time from source to destination exceeds the duration of the current time interval, the output signal does not contain all contributions from the current time interval input.
Parameters
Backscatter pattern frequency vector - frequency of the broadband backscatter pattern
[0.1e20 Hz] (by default) | ` real vector of positive values in strictly increasing order`
Specifies the frequencies used in the EPR matrix. The elements of this vector must be in strictly ascending order. The target does not respond outside this frequency range. Frequencies are specified relative to the physical frequency band, not the baseband. The unit of frequency measurement is Hz.
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Azimuth angles (°) - azimuth angles
[-180:180] (by default) | real vector row 1 by P | real vector column P by 1
The azimuth angles used to determine the angular coordinates of each column of matrices given by the RCS pattern (m^2) parameters as vector-string 1 on P or vector-column P on 1. P must be greater than 2. Azimuth angles must lie in the range from −180° to 180° inclusive. The units of angles are degrees (°).
Example: [-45:0.1:45]
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Elevation angles (°) - angles of place
[-90:90] (by default) | real vector row 1 by Q | real vector column Q by 1
The angles of place used to determine the angular coordinates of each column of matrices given by the parameters RCS pattern (m^2) as a vector-string of 1 on Q or a vector-column of Q on 1. Q must be greater than 2. Place angles must lie in the range from −90° to 90° inclusive. The units of angles are degrees (°).
Example: [-30:0.1:30]
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
RCS pattern (m^2) - radar cross-sectional pattern
ones(181,361) | real matrix Q on P | real array Q on P on K | real array 1 on P on K | real matrix K on P
A radar cross-section diagram given as a real matrix or array.
| Dimensions | Applications |
|---|---|
Matrix Q to P |
The matrix of EPR values is given as a function of elevation angles Q and azimuth P. The same EPR matrix is used for all frequencies. |
Array Q to P to K |
The EPR pattern array is specified as a function of elevation angles Q, azimuth angles P, and frequencies K. If K = 1, the EPR template array is equivalent to the Q matrix on P. |
Array 1 on P on K |
A matrix of EPR values is specified as a function of azimuth angles P and frequencies K. These dimension formats apply when there is only one elevation angle. |
Matrix K at P |
-
Q is the length of the vector given by the Elevation angles (deg) parameters.
-
P is the length of the vector given by the Azimuth angles (deg) parameters.
-
K - number of frequencies specified by the Backscatter pattern frequency vector (Hz) parameters.
You can specify patterns for L targets by putting L patterns in a column vector. All patterns must have the same size. The L value must match the column sizes of the signals sent to the block input, but you can use one pattern to model multiple targets.
The units of EPR measurement are square metres.
*Example: [1,2;2,1]
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Fluctuation model - fluctuation model
Nonfluctuating (by default) | Swerling1 | Swerling2 | Swerling3 | Swerling4
Specify the fluctuating target model as one of the options: Nonfluctuating, Swerling1, Swerling2, Swerling3 or Swerling4.
If you set this parameter to a value other than Nonfluctuating, either true or false must be passed to the Update port.
Propagation speed (m/s) - signal propagation speed
299792458 (By default) | positive scalar
Signal propagation speed as a real positive scalar. By default, the value of the speed of light (299792458 m/s) is used.
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64.
Operating frequency (Hz) - carrier frequency of the signal
3e8 (by default) | positive scalar
Carrier frequency of the signal specified as a positive real scalar. The unit of measurement is Hz.
Inherit sample rate - inherit sample rate
On (by default) | Off.
Select the checkbox to inherit sample rate from upstream blocks. Otherwise, set the sample rate using the Sample rate (Hz) parameters.
Sample rate (Hz) - sampling rate
1e6 (By default) | Positive scalar
The sampling frequency of the signal as a positive scalar. The unit of measurement is Hz.
Dependencies
To use this parameters, clear the Inherit sample rate checkbox.
Data types: Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64, Bool.
Number of subbands - number of processing subranges
1e6 (by default) | positive integer
The number of processing subbands specified as a positive integer.
*Example: 128