How to use CFAR algorithm in my case

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Chen yuru 2019-11-14

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https://ww2.mathworks.cn/matlabcentral/answers/491146-how-to-use-cfar-algorithm-in-my-case

编辑： Alaa Eddin Ziadah 2020-12-15

test.mat

在 MATLAB Online 中打开

Hello,

I have a spectrum in test.mat. (as shown in Figure, size is 1024 x 32)

I would like to do CFAR to detect tearget.

I reference Constant False Alarm Rate (CFAR) Detection in matlab code.(link as shown in below)

https://www.mathworks.com/help/phased/examples/constant-false-alarm-rate-cfar-detection.html

But it doesn't work.

----------------------

It appears error:

Error using step

Expected Row 2 of Idx to be an array with all of the values <= 32.

Error in sigdatatypes.validateIndex (line 36)

validateattributes(x,type,varargin{2},funcname,varname);

Error in phased.CFARDetector2D/stepImpl (line 320)

sigdatatypes.validateIndex(Idx(2,:),'step','Row 2 of Idx',...

---------------------

Could you please tell me how to revised the code.

Thanks!

load test.mat
cfar2D = phased.CFARDetector2D('GuardBandSize',2,'TrainingBandSize',5,...
  'ProbabilityFalseAlarm',1e-5);
dopGrid = 1:1024;
rngGrid = 1:32;
[~,rangeIndx] = min(abs(rngGrid'-[1 32]));
[~,dopplerIndx] = min(abs(dopGrid'-[1 1024]));
[columnInds,rowInds] = meshgrid(dopplerIndx(1):dopplerIndx(2),...
  rangeIndx(1):rangeIndx(2));
CUTIdx = [rowInds(:) columnInds(:)]';
detections = cfar2D(test,CUTIdx);
helperDetectionsMap(test,rngGrid,dopGrid,rangeIndx,dopplerIndx,detections)