# phased.GLRTDetector

## Description

The generalized likelihood ratio test detector (GLRT) can detect signals with unknown
parameters in the presence of noise. Unknown parameters include signal amplitude, phase,
frequency, and arrival times. The detector replaces unknown parameters with their maximum
likelihood estimates under the signal absent hypothesis *H*_{0
} or the alternative signal present hypothesis *H*_{1
} and then uses the LRT detector to output detection results.

Create the

`phased.GLRTDetector`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

## Creation

### Description

creates a
generalized likelihood ratio test `detector`

= phased.GLRTDetector`detector`

System object™ with default properties.

creates a likelihood ratio test `detector`

= phased.GLRTDetector(`Name`

= `Value`

)`detector`

System object with the 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

Unless otherwise indicated, properties are *nontunable*, which means you cannot change their
values after calling the object. Objects lock when you call them, and the
`release`

function unlocks them.

If a property is *tunable*, you can change its value at
any time.

For more information on changing property values, see System Design in MATLAB Using System Objects.

`DataComplexity`

— Data complexity

`'Complex'`

(default) | `'Real'`

Data complexity, specified as `'Complex'`

or `'Real'`

.
Complexity defines the format used to report output data. When
`DataComplexity`

is `'Complex'`

, data is
complex-valued. When `DataComplexity`

is `'Real'`

,
data is real-valued.

**Example: ** `'Real'`

**Data Types: **`char`

| `string`

`ProbabilityFalseAlarm`

— Probability of false alarm

`1e-1`

(default) | nonnegative scalar

Probability of false alarm, specified as a positive scalar between 0 and 1, inclusive.

**Example: **`1e-6`

**Data Types: **`single`

| `double`

`OutputFormat`

— Format of output data

`'Detection result'`

(default) | `'Detection index'`

Format of output data, specified as `'Detection result'`

or `'Detection index'`

. Output data is returned in the `Y`

argument.

**Example: **`'Detection index'`

**Data Types: **`char`

| `string`

`ThresholdOutputPort`

— Output detection statistics and threshold

`false`

(default) | `true`

Output detection statistics and detection threshold, specified as `false`

or `true`

. Set this property to `true`

to output the detection statistics in the `stat`

argument and the detection threshold in the `th`

argument. Set this property to `false`

to suppress the output of detection statistics and threshold.

**Data Types: **`logical`

`NoiseInputPort`

— Enable input of known noise power

`false`

(default) | `true`

Enable the input of noise power, specified as `false`

or
`true`

. You can input known or estimated noise power from a reference
source. When `true`

, use the input argument `ncov`

to specify noise power. When `false`

, the noise input port is disabled
and the noise power is estimated by the GLRT detector.

**Data Types: **`logical`

`SignalParameterOutputPort`

— Output maximum likelihood estimate of unknown signal parameters

`false`

(default) | `true`

Output the maximum likelihood estimates of the unknown signal parameters under the
alternative hypothesis (*H*_{1}), specified as
`false`

or `true`

. Parameters are output in the
`estparam`

argument.

**Data Types: **`logical`

`NoisePowerOutputPort`

— Output estimated noise power

`false`

(default) | `true`

Output the estimated noise power, under the alternative hypothesis. Noise power is
output in the `estnoise`

argument.

#### Dependencies

To enable this property, set the `NoiseInputPort`

property to
`false`

.

**Data Types: **`logical`

## Usage

### Syntax

### Description

You can combine optional input and output arguments when their enabling properties are
set. Optional inputs and outputs must be listed in the same order as the order of the
enabling properties. For example, ```
[Y,stat,th,estparam] =
detector(X,hyp,obs,ncov)
```

.

### Input Arguments

`X`

— Input data

*N*-by-1 real-valued vector | *N*-by-1 complex-valued vector | *N*-by-*M* real-valued matrix | *N*-by-*M* complex-valued matrix

Input data, specified as a real-valued or complex-valued *N*-by-1
vector, or an *N*-by-*M* real-valued or
complex-valued matrix. *N* is the signal length and
*M* is the number of data channels. Detection is performed along
the columns of `X`

. The size of each row *M*
cannot change during simulation. When *M* = 1, `X`

represents a single channel of data. When *M *> 1,
`X`

can represent *N* samples from
*M* data channels. Data streams can later be combined, for example,
by beamforming.

The input data has a general interpretation. For example, the data can be interpreted as:

Time series –

*N*samples of a time seriesSensor -

*N*represents a snapshot of data samples from a set of sensors

**Data Types: **`single`

| `double`

**Complex Number Support: **Yes

`hyp`

— Augmented linear equality constraint matrix

real-valued *R*-by-(*P* + 1) matrix | complex-valued *R*-by-(*P* + 1) matrix

Augmented linear equality constraint matrix, specified as a real-valued or
complex-valued *R*-by-(*P* + 1) matrix. The matrix
takes the form `[A,b]`

representing the equation:

$$A\Theta =b$$

where the unknown parameters are represented by ϴ.
`A`

has the rank *R* ≥ 1. The augmented linear
equality constraint matrix expresses the null hypothesis
*H*_{0}.

For this signal model, the GLRT detector determines whether to reject the null
hypothesis which is expressed in the form `A*θ = b`

where
`A`

is an *R*-by-*P* matrix with
*R ≤ P* and rank *R ≥ 1*. `b`

is
an *R*-by-1 vector. `A`

and `b`

are
carried in the augmented linear equality constraint matrix ```
hyp =
[A,b]
```

. Because there are *D* signal models, the GLRT
detector outputs *D* detection results for each column of
`X`

**Data Types: **`single`

| `double`

**Complex Number Support: **Yes

`obs`

— Observation matrix

*N*-by-*P*-by-*D*
array

Observation matrix for the linear deterministic signal model, specified as an
*N*-by-*P*-by-*D* array
*N > p* and rank *P*, *D* is the
number of signal models, and the white Gaussian `noise`

is a
*N*-by-1 vector determined by the covariance
`ncov`

argument. The observation matrix is defined by
`X`

= `obs`

*`param`

+
`noise`

,

**Example: **20.0

**Data Types: **`single`

| `double`

**Complex Number Support: **Yes

`ncov`

— Known noise power

positive scalar

Known noise power, specified as a scalar or a row vector of length
*D*. When `ncov`

is a scalar, it represents
equal known noise power for *D* models. When
`ncov`

is a row vector of length *D*, it
represents the known noise power for the *D* models,
respectively.

**Example: **`20.0`

#### Dependencies

To enable this argument, set the `NoiseInputPort`

property to
`true`

.

**Data Types: **`single`

| `double`

### Output Arguments

`Y`

— Detection results

*D*-by-*M* logical-valued vector | 1-by-*L* integer-valued vector | 2-by-*L* integer-valued matrix

Detection results of *D* models for *M*
independent data samples returned as a *D*-by-*M*
logical-valued vector, 1-by-*L* integer-valued vector, or
2-by-*L* integer-valued matrix. The format of
`Y`

depends on how the `OutputFormat`

property
is specified. By default, the `OutputFormat`

property is set to
`'Detection result'`

.

When `OutputFormat`

is `'Detection result'`

,
`Y`

is a *D*-by-*M* matrix
containing logical detection results, where *D* is the number of
signal models and *M* is the number of columns of
`X`

. For each row, *Y* is
`true`

in a column if there is a detection in the corresponding
column of `arg`

. Otherwise, `Y`

is
`false`

.

When `OutputFormat`

is `'Detection index'`

,
`Y`

is a 1-by-`L`

vector or a
2-by-*L* matrix containing detection indices, where
*L* is the number of detection found in the *M*
data samples and *D* models. When `X`

is a column
vector, *Y* is a 1-by-*L* vector and contains the
index of the detections found in the *D* models. When
`X`

is a matrix, `Y`

is a
2-by-*L* matrix, and each column of `Y`

has the
form `[detrow;detcol]`

, where `detrow`

is the index
of the model and `detcol`

is the column index of
`X`

.

`stat`

— detection statistic

*N*-by-*M* (default) | 1-by-*L*

Detection statistics, returned as a *N*-by-*M*
matrix or 1-by-*L* vector. The format of `stat`

depends on the `OutputFormat`

property.

When

`OutputFormat`

is`'Detection result'`

,`stat`

has the same size as`Y`

.When

`OutputFormat`

is`'Detection index'`

,`stat`

is a 1-by-*L*vector containing detection statistics for each corresponding detection in`Y`

.

`th`

— Detection threshold

scalar

Detection threshold, returned as a scalar.

#### Dependencies

To enable this argument, set the `ThresholdOutputPort`

property to `true`

.

`estparam`

— Maximum likelihood estimates of signal parameters

*P*-by-*M*-by-*D*
array

Maximum likelihood estimates (MLE) of unknown signal parameters, returned as a
*P*-by-*M*-by-*D* array.

#### Dependencies

To enable this argument, set the `SignalParameterOutputPort`

property to `true`

.

`estnoise`

— Estimated noise power

positive scalar

Estimated noise power, returned as a positive scalar. When the
`OutputFormat`

property is `'Detection result'`

,
`estnoise`

has the same size as `Y`

. When
`OutputFormat`

property is `'Detection index'`

,
`estnoise`

returns a noise power estimate of size
1-by-*L* for each corresponding detection in
`Y`

.

#### Dependencies

To enable this argument, set the `NoisePowerOutputPort`

property to `true`

.

## Object Functions

To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named `obj`

, use
this syntax:

release(obj)

## Examples

### Generalized Likelihood Ratio Test Detection on Real Data

Perform GLRT detection on a real Gaussian noise matrix with a desired probability of false alarm of 0.1. Assume that the signal dimension is 4, the noise power is unknown, and there are 2 unknown signal parameters with true values 0. Use a 3-model observation matrix. Perform the detection on all samples of the input and evaluate the probability of false alarm.

rng(10031); glrt = phased.GLRTDetector( ... DataComplexity = 'Real', ... ProbabilityFalseAlarm = 0.1); N = 4; M = 1000; p = 2; D = 3; x = randn(N,M); hyp = [eye(p) zeros(p,1)]; obs = randn(N,p,D); dresult = glrt(x,hyp,obs); Pfa = sum(dresult,2)/M

`Pfa = `*3×1*
0.0970
0.1030
0.1110

### Generalized Likelihood Ratio Threshold Detection on Complex Data

Perform Generalized Likelihood Ratio Threshold detection on complex Gaussian noise matrix with a desired probability of false alarm of 0.1. Assume that the signal dimension is 5. Also assume that the noise power is unknown. Assume there is only one unknown signal parameter with a true value zero. Use a single-model observation matrix. Perform the detection on all samples of the input and evaluate the probability of false alarm.

rng default glrt = phased.GLRTDetector(DataComplexity = 'Complex', ... ProbabilityFalseAlarm = 0.1); N = 5; M = 1000; x = 1/sqrt(2)*(randn(N,M)+1i*randn(N,M)); hyp = [1 0]; obs = ones(N,1); dresult = glrt(x,hyp,obs); Pfa = sum(dresult)/M

Pfa = 0.1060

### Perform Generalized Likelihood Ratio Test Detection

Perform GLRT detection on a complex Gaussian noise matrix with a desired probability of false alarm of 0.1. Assume that the signal dimension is 2 and that the noise power is unknown. There is only 1 unknown signal parameter with true value 0. Use a single-model observation matrix. Perform the detection on all samples of the input and evaluate the probability of false alarm.

Create the 1000 samples of Gaussian random data.

```
rng default
N = 2;
M = 1000;
x = 1/sqrt(2)*(randn(N,M) + 1i*randn(N,M));
```

Create the GLRT detector System object™.

glrt = phased.GLRTDetector(DataComplexity = 'complex', ... ProbabilityFalseAlarm = 0.1);

Specify the observation and hypotheses matrices.

hyp = [1 0]; obs = ones(N,1);

Solve and display the first 15 of the detection results.

dresult = glrt(x,hyp,obs); disp(dresult(1:15))

0 0 0 0 1 0 0 0 0 1 0 0 0 0 0

Estimate the probability of false alarm.

Pfa = sum(dresult)/M

Pfa = 0.0930

The probability of false alarm is close to the desired probability of 0.1.

### Perform Generalized Likelihood Ratio Test Detection For Two Parameters

Perform GLRT detection on a given complex Gaussian noise matrix with a desired probability of false alarm of 0.1. Assume that the signal dimension is 4 and the noise power is unknown. There are 2 unknown signal parameters with true values 0. Use a 3-model observation matrix. Perform the detection on all samples of the input and evaluate the probability of false alarm.

Create the random data.

```
rng default
N = 4;
M = 1000;
P = 2;
D = 3;
x = 1/sqrt(2)*(randn(N,M)+1i*randn(N,M));
```

Create the `phased.GLRTDetector`

System object™.

glrt = phased.GLRTDetector(DataComplexity = 'complex', ... ProbabilityFalseAlarm = 0.1); hyp = [eye(P) zeros(P,1)]

`hyp = `*2×3*
1 0 0
0 1 0

obs = randn(N,P,D) + 1i*randn(N,P,D);

Run the detector and compute the probability of false alarm.

dresult = glrt(x,hyp,obs); pfa = sum(dresult,2)/M

`pfa = `*3×1*
0.0890
0.0980
0.0970

### Perform Angle-Domain GLRT Detection of Two Targets

Perform angle-domain GLRT detection for two targets located at 11 and -47 degrees with a desired probability of false alarm of 0.01. Use a ULA of dimension 128 to receive a single-snapshot signal with complex white Gaussian noise. The noise power and target complex amplitudes are unknown. Use a 256-model observation matrix, where each model checks the existence of a target following that model. Perform the detection on the input and plot the detection result.

rng default glrt = phased.GLRTDetector(DataComplexity = 'complex', ... ProbabilityFalseAlarm = 0.01);

Create two targets located at 11 and -47 degrees.

tarAng = [11,-47]; tarNum = length(tarAng);

Start with a ULA array with 128 elements having 1/2-wavelength element spacing.

```
N = 128;
fc = 3e8;
elementPos = (0:N-1)*physconst('LightSpeed')/fc/2;
```

Create single-snapshot received signal from two targets at the ULA.

tarAmp = 1/sqrt(2)*(randn(tarNum,1) + 1i*randn(tarNum,1)); signal = steervec(elementPos,tarAng)*tarAmp;

Single-snapshot of complex white Gaussian noise at the ULA.

noise = 1/sqrt(2)*(randn(N,1) + 1i*randn(N,1));

Add the noise to the signal.

x = signal + noise;

Partition angle into 256 angle bins

D = 256; angGrid = asind(2*(-D/2:D/2-1)/D);

Perform GLRT detection on 256 signal models. Each model assumes one target. % N-by-1-by-D

obs = permute(steervec(elementPos,angGrid),[1 3 2]); hyp = [1,0]; dresult = glrt(x,hyp,obs);

Plot the GLRT detection results at the 256 angle bins.

plot(angGrid,dresult) xlabel('Angle (degrees)') ylabel('Detection Result') grid on

### Perform Angle-Doppler-Domain GLRT Detection

Perform angle-Doppler-domain GLRT detection for a target located at 28 degree at a Doppler of 10 Hz with a desired probability of false alarm of 1e-6. Use a ULA of dimension 128 to receive a 32-pulse signal under complex white Gaussian noise. The noise power and target complex amplitude are unknown. Use a observation matrix with 256-by-64 angle-Doppler models, where each model checks the existence of a target following that model. Perform the detection on the input and plot the spatial-temporal detection map.

rng default glrt = phased.GLRTDetector('DataComplexity','complex',... 'ProbabilityFalseAlarm',1e-6,... 'ThresholdOutputPort',true);

Target is located at 28 degree at a Doppler of 10 Hz.

tarAng = -28; tarDop = 10;

Create a ULA with 128 elements and with elements spaced at 1/20-wavelength.

```
elementNum = 128;
fc = 3e8;
elementPos = (0:elementNum-1)*physconst('LightSpeed')/fc/2;
```

ULA observes 32 pulses at a PRF of 50 Hz

fPRF = 50; pulseNum = 32;

Create the spatial-temporal signal from the target at the ULA.

tarAmp = 1/sqrt(2)*(randn + 1i*randn); dopSv = dopsteeringvec(tarDop,pulseNum,fPRF); angSv = steervec(elementPos,tarAng); signal = kron(dopSv,angSv)*tarAmp;

Add the spatial-temporal complex white Gaussian noise at the ULA.

noisePow = 0.01; N = elementNum*pulseNum; noise = sqrt(noisePow/2)*(randn(N,1) + 1i*randn(N,1)); x = signal + noise;

Partition angle into 256 angle bins and Doppler into 64 Doppler bins

angNum = 256; dopNum = 64; angGrid = asind(2*(-angNum/2:angNum/2-1)/angNum); dopGrid = fPRF*(-dopNum/2:dopNum/2-1)/dopNum; D = angNum*dopNum;

Perform GLRT detection on 256-by-64 angle-Doppler models, each assuming 1 target.

obs = zeros(N,1,D); for dopBin = 1:dopNum dopGridSv = dopsteeringvec(dopGrid(dopBin),pulseNum,fPRF); for angBin = 1:angNum angGridSv = steervec(elementPos,angGrid(angBin)); angDopGridSv = kron(dopGridSv,angGridSv); obs(:,:,(dopBin-1)*angNum+angBin) = angDopGridSv; end end hyp = [1,0]; [dresult,stat,th] = glrt(x,hyp,obs); stat = reshape(stat,angNum,dopNum);

Plot a spatial-temporal GLRT detection map.

[dopMesh,angMesh] = meshgrid(dopGrid,angGrid); surf(angMesh,dopMesh,pow2db(stat)) hold on mesh(angMesh,dopMesh,pow2db(th)*ones(angNum,dopNum)) xlabel('Angle (degrees)') ylabel('Doppler (Hz)') zlabel('Power (dB)')

## More About

### Data Precision

This System object supports single and double precision for input data, properties and arguments. If input data is single precision, all the non-logical outputs are also single precision. If input data is double precision, the non-logical outputs are double precision. The precision of the non-logical output is independent of the precision of the properties and other arguments.

### Signal Model

The GLRT detector assumes *D* linear deterministic signals in each
column of `X`

. The GLRT detector assumes that the data follows the linear
deterministic signal model `X = H*param + noise`

where
`X`

is an *N*-by-1 data vector, ` H`

the observation matrix given as an
*N*-by-*P*-by-*D* array.

`param`

is a*P*-by-1 vector that contains*P*unknown signal parameters.`H`

is an*N*-by-*P*-by-*D*array that summarizes*D*observation matrices of size*N*-by-*P*with*N > p\P*and rank*P*.`noise`

is an*N*-by-1 noise vector assumed to be white Gaussian.

For this signal model, the GLRT detector determines whether to reject the
null hypothesis. The null hypothesis is expressed in the form `A*param = b`

where `A`

is an *R*-by-*P* matrix with
*R ≤ P* and rank *R ≥ 1*, and `b`

is an
*R*-by-1 vector. `A`

and `b`

are form
the augmented linear equality constraint matrix `hyp = [A,b]`

. Because
there are *D* signal models, the GLRT detector outputs *D*
detection results for each column of `X`

.

`H`

is the observation matrix for a linear deterministic signal model
`X = H*param + noise`

. `obs`

is an
*N*-by-*P*-by-*D* array with ```
N
> p
```

and with rank `p`

, *D* is the number of
signal models, and `noise`

is a white Gaussian noise
*N*-by-1 vector.

The GLRT algorithm replaces the unknown parameters by their maximum likelihood estimates
under the *H*_{0} or
*H*_{1} hypotheses. Subsequently, the algorithm
applies the likelihood ratio test. For a data vector x with unknown model parameters ϴ, the
GLRT decides *H*_{1} if the likelihood ratio is greater
than the threshold η

$$\frac{p(x,{\widehat{\Theta}}_{1},{H}_{1})}{p(x,{\widehat{\Theta}}_{0},{H}_{0})}>\eta $$

for the estimated ϴ.

### Detection Statistics and Threshold

For a real data model with known Gaussian white noise, the test statistic is given by

$$T(x)=\frac{{\left(A{\widehat{\theta}}_{1}-b\right)}^{T}{\left(A{({H}^{T}H)}^{-1}{A}^{T}\right)}^{-1}\left(A{\widehat{\theta}}_{1}-b\right)}{{\sigma}^{2}}$$

where $${\widehat{\theta}}_{1}$$ represents the maximum likelihood estimate of θ given by

$${\widehat{\theta}}_{1}={\left({H}^{T}H\right)}^{-1}{H}^{T}x$$

For a complex data model with known Gaussian noise, the test statistic is given by

$$T(x)=2\frac{{\left(A{\widehat{\theta}}_{1}-b\right)}^{\u2020}{\left(A{({H}^{\u2020}H)}^{-1}{A}^{\u2020}\right)}^{-1}\left(A{\widehat{\theta}}_{1}-b\right)}{{\sigma}^{2}}$$

where *H*^{†} denotes the
adjoint of *H* where

$${\widehat{\theta}}_{1}={\left({H}^{\u2020}H\right)}^{-1}{H}^{\u2020}x$$

For the real data model with unknown white Gaussian noise. the test statistic is

$$T(x)=\frac{1}{r}\frac{{\left(A{\widehat{\theta}}_{1}-b\right)}^{T}{\left(A{({H}^{T}H)}^{-1}{A}^{T}\right)}^{-1}\left(A{\widehat{\theta}}_{1}-b\right)}{{\widehat{\sigma}}^{2}}$$

where again the maximum likelihood estimate of θ is represented by $${\widehat{\theta}}_{1}$$

$${\widehat{\theta}}_{1}={\left({H}^{T}H\right)}^{-1}{H}^{T}x$$

. but here σ² is estimated by

$$\begin{array}{l}{\widehat{\sigma}}^{2}=\frac{1}{N-p}{\Vert {P}_{H}^{\perp}x\Vert}^{2}\\ {P}_{H}^{\perp}=I-H{(}^{{H}^{T}}{H}^{T}\end{array}$$

For complex data with unknown Gaussian noise, the test statistic is

$$T(x)=\frac{1}{r}\frac{{\left(A{\widehat{\theta}}_{1}-b\right)}^{\u2020}{\left(A{({H}^{\u2020}H)}^{-1}{A}^{\u2020}\right)}^{-1}\left(A{\widehat{\theta}}_{1}-b\right)}{{\widehat{\sigma}}^{2}}$$

where

$${\widehat{\theta}}_{1}={\left({H}^{\u2020}H\right)}^{-1}{H}^{\u2020}x$$

and the estimate of σ² is

$$\begin{array}{l}{\widehat{\sigma}}^{2}=\frac{1}{N-p}{\Vert {P}_{H}^{\perp}x\Vert}^{2}\\ {P}_{H}^{\perp}=I-H{(}^{{H}^{H}}{H}^{H}\end{array}$$

The detection threshold for real data with known white Gaussian noise and a given
theoretical probability of false alarm *P*_{fa} is
calculated from the chi-square inverse cumulative distribution function (CDF) with
*r* degrees of freedom.

$$\gamma =\text{chi2inv}(1-{P}_{\text{fa}},r)$$

For complex data with known white Gaussian noise and a given theoretical probability of
false alarm *P*_{fa}, the theoretical detection
threshold is calculated from the chi-square inverse cumulative distribution function (CDF)
with *2r* degrees of freedom

$$\gamma =\text{chi2inv}(1-{P}_{\text{fa}},2r)$$

For real data with unknown white Gaussian noise and a given theoretical probability of
false alarm *P*_{fa}, the theoretical detection
threshold calculated from the `f-inverse cumulative distribution function`

(CDF) with *r* degrees of freedom

$$\gamma =\text{finv}(1-{P}_{\text{fa}},r,N-p)$$

For complex data with unknown white Gaussian noise and a given theoretical probability
of false alarm *P*_{fa}, the theoretical detection
threshold is calculated from the ```
f-inverse cumulative distribution
function
```

(CDF) with *2r* degrees of freedom

$$\gamma =\text{finv}(1-{P}_{\text{fa}},2r,2(N-p))$$

## References

[1] Steven M. Kay,
*Fundamentals of Statistical Signal Processing, Detection Theory*,
Prentice-Hall PTR, 1993.

[2] Mark A. Richards,
*Fundamentals of Radar Signal Processing*, Third edition, McGraw-Hill
Education, 2022.

## Extended Capabilities

### C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

## Version History

**Introduced in R2023b**

## See Also

`phased.LRTDetector`

| `npwgnthresh`

| `rocsnr`

| `rocpfa`

| `phased.CFARDetector`

| `phased.CFARDetector2D`

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