phased.CFARDetector2D
Two-dimensional CFAR detector
Description
phased.CFARDetector2D
System object™ implements a constant false-alarm rate detector (CFAR) for selected
elements (called cells) of two-dimensional image data. A detection is declared when an
image cell value exceeds a threshold. To maintain a constant false alarm-rate, the
threshold is set to a multiple of the image noise power. The detector estimates noise
power for a cell-under-test (CUT) from surrounding cells using
one of three cell averaging methods, or an order statistics method. The cell-averaging
methods are cell averaging (CA), greatest-of cell averaging (GOCA), or smallest-of cell
averaging (SOCA).
For each test cell, the detector:
estimates the noise statistic from the cell values in the training band surrounding the CUT cell.
computes the threshold by multiplying the noise estimate by the threshold factor.
compares the CUT cell value to the threshold to determine whether a target is present or absent. If the value is greater than the threshold, a target is present.
To run the detector
Define and set up your 2-D CFAR detector. You can set the
phased.CFARDetector2D
System object properties when you create the object, or leave them set to their default values. See Construction. Some properties that you set at construction time can be changed later. These properties are tunable.Find the detections by calling the
step
method. The output of this method depends on the properties of thephased.CFARDetector2D
System object.
Note
Alternatively, 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
creates a
2-D CFAR detector System object, detector
= phased.CFARDetector2Ddetector
.
creates a 2-D CFAR System object, detector
= phased.CFARDetector2D(Name
,Value
)detector
, 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
Methods
reset | Reset states of System object |
step | Two-dimensional CFAR detection |
Common to All System Objects | |
---|---|
release | Allow System object property value changes |
Examples
More About
Algorithms
References
[1] Mott, H. Antennas for Radar and Communications. New York: John Wiley & Sons, 1992.
[2] Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.
[3] Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.
Extended Capabilities
Version History
Introduced in R2016b