SAR image focusing quality evaluation plug-in

Catalog

summary

Plug in instructions

SARImageFocusedQuality1

function

Call mode and interface

Working principle and process

Call example

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word Documents and related codes can be downloaded through the following connection ：

SAR Image focusing quality evaluation plug-in _release.zip- Image processing document resources -CSDN download SAR Image focusing quality evaluation plug-in resolution peak sidelobe ratio integral sidelobe ratio radiation quality evaluation more download resources 、 For learning materials, please visit CSDN Download channel .https://download.csdn.net/download/smyounger/85308321

summary

Introducing SAR Signal properties and imaging processing algorithm , Let's first introduce SAR Focus on quality evaluation , Only with this scheme can we evaluate the imaging processing algorithm introduced later . evaluation SAR The important indexes of focusing of imaging processing software include resolution 、 Peak sidelobe ratio 、 Integral sidelobe ratio .

The following has been combined with sinc function , The resolution of one-dimensional signal is introduced 、 Peak sidelobe ratio 、 Definition and calculation method of integral sidelobe ratio .

SAR Related indicators _sinc Function and SAR Point target focus index —— The resolution of the 、 Peak sidelobe ratio 、 Integral sidelobe ratio _ Xiaowei, who loves learning, has a blog -CSDN Blog _ Integral sidelobe ratio sinc function https://blog.csdn.net/smyounger/article/details/122643307?spm=1001.2014.3001.5501

This section focuses on SAR Interface and usage of image focusing quality evaluation plug-in .

Plug in instructions

SARImageFocusedQuality1

function

Test the focusing index of single view complex image , Include point target peak , Azimuth resolution 、 Peak sidelobe ratio and integral sidelobe ratio , Range resolution 、 Peak sidelobe ratio and integral sidelobe .

Call mode and interface

Call mode ：[Radiopara, Rgpara, Azpara] = SARImageFocusedQuality(sig_in, prf, sampleRate, Vg, sliceSize, interpNum)

  Input parameters ：

    sig_in: Input single view complex image , It is recommended to center on the scaler , Cut a slice , Improve the efficiency of program operation

    prf: Pulse repetition rate , Company Hz

    sampleRtae: Sampling rate , Company Hz

    Vg: Beam ground speed , Company m/s

    slizeSize: When measuring indexes , Centered on the maximum （ Scaler ）, Cut a size of slizeSize*slizeSize The section of

    interpNum: Interpolation multiple , When measuring the index, the signal shall be interpolated

  Output parameters ：

    Radiopara: Point target radiation related indicators

      Radiopara.peakVal: Peak point amplitude

      Radiopara.posa: Peak point azimuth pixel coordinates

      Radiopara.posr： Peak point distance to pixel coordinates

    Rgpara: Range focus index

      Rgpara.res： Range resolution , Company m

      Rgpara.PSLR： Distance peak sidelobe ratio , Company dB

      Rgpara.ISLR： Range integral sidelobe ratio , Company dB

    Azpara: Azimuthal focus index

      Azpara.res： Azimuth resolution , Company m

      Azpara.PSLR： Azimuth peak sidelobe ratio , Company dB

      Azpara.ISLR： Azimuth integral sidelobe ratio , Company dB

Working principle and process

The basic process of function work ：

• Find the brightest point in the scene , And think that this point is the scaler ;
  1. Output the pixel coordinates of the scaler [Radiopara.posa, Radiopara.posr];
• Centering on the scaler , Cut a size of sliceSize* sliceSize The section of ;
• The slices are interpNum Times two-dimensional interpolation ;
• Search for the maximum brightness after interpolation ;
  1. Peak amplitude of output calibration Radiopara.peakVal
• At the peak point after interpolation , Cut a distance signal , Test and output the distance indicator ：
  1. Rgpara.res： Range resolution , Company m
  2. Rgpara.PSLR： Distance peak sidelobe ratio , Company dB
  3. Rgpara.ISLR： Range integral sidelobe ratio , Company dB
• At the peak point after interpolation , Cut an azimuth signal , Test and output the azimuth indicator
  1. Azpara.res： Azimuth resolution , Company m
  2. Azpara.PSLR： Azimuth peak sidelobe ratio , Company dB
  3. Azpara.ISLR： Azimuth integral sidelobe ratio , Company dB：

When calling the program , The input single view complex image is suggested to be a manually intercepted slice , And there is only one strong target in the intercepted image , Otherwise, this plug-in will only measure the indicators of the strongest points , Ignore other points .

Call example

%SAR Image focusing quality evaluation 
%  Use the pre generated point target simulation data 
% Young 2022-05-06
close all
clear all

%%
load testData.mat;

%%
sliceSize = 32;
interpNum = 16;
pointSize = 512;

[Radiopara, Rgpara, Azpara] = ...
    SARImageFocusedQuality1(sig_image, prf, sampleRate, Vst, sliceSize, interpNum);
fprintf(' Slice peak ： %f,  coordinate ：[%d, %d]\n', Radiopara.peakVal, Radiopara.posa, Radiopara.posr);
fprintf('-------  Distance indicator  -------\n');
fprintf(' Peak value ： %8.2f ',Rgpara.max);
fprintf('    The resolution of the ： %4.3f', Rgpara.res);
fprintf('    Peak sidelobe ratio ：%5.3f', Rgpara.PSLR);
fprintf('   Integral sidelobe ratio ：%5.3f\n', Rgpara.ISLR);
fprintf('-------  Azimuth indicator  -------\n');
fprintf(' Peak value ： %8.2f ',Azpara.max);
fprintf('    The resolution of the ： %4.3f', Azpara.res);
fprintf('    Peak sidelobe ratio ：%5.3f', Azpara.PSLR);
fprintf('   Integral sidelobe ratio ：%5.3f\n', Azpara.ISLR);

Run the above program , The plug-in outputs the interpolated point target , As shown in the figure below .

  The plug-in outputs the one-dimensional signal waveform and spectrum after interpolation , As shown in the figure below

  The indicators of program output are shown in the figure below .

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