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Hamming linear aperture; modulated speckle images; contours; cross-correlation.

In this paper, a new concentric Hamming linear aperture is suggested. The point spread function (PSF) is computed for concentric Hamming linear aperture and it is compared with the corresponding circular, conventional Hamming and obstructed Hamming apertures. In addition, the autocorrelation corresponding to the aperture under consideration is computed and plotted. Application of the Hamming linear aperture in the formation of modulated speckle images of Ramses II statues using definite random diffuser is given. A diffuser limited by a circular uniform aperture is the basic element in the formation of ordinary speckle images located in the Fourier plane. Meanwhile,the Fourier spectrum of images of Ramses II multiplied by the ordinary speckle give modulated speckle images. Discrimination between the modulated speckle images is justified by comparing the profiles corresponding to each speckle image. Finally, the speckle contours and correlation of the modulated speckle images compared to the ordinary speckle images are investigated. It is noted that all computation and formation of images and plots are based on fast Fourier transform (FFT) techniques using Matlab codes.

A M HAMED

Published

16 August 2020

Manuscript received

19 January 2020

Manuscript revised

15 March 2020

Accepted

9 April 2020

Final version published online

16 August 2020