Preferred Language
Articles
/
ijs-12063
Describing the Wavefront Aberrations of the Hexagonal Aperture Using Modified Zernike Polynomials

The concept of the optical telescope is the primary mirror design, the Next Generation Segmented Optical Telescope (NGST) with hexagonal segment of spherical primary mirror can provide a 3 arc minutes field of view. Extremely Large Telescopes (ELT) in the 100m dimension would have such unprecedented scientific effectiveness that their construction would constitute a milestone comparable to that of the invention of the telescope itself and provide a truly revolutionary insight into the universe. The scientific case and the conceptual feasibility of giant filled aperture telescopes was our interested. Investigating the requirements of these imply for possible technical options in the case of a 100m telescope. For this telescope the considerable interest is the correction of the optical aberrations for the coming wavefront, the modified Zernike polynomials for hexagonal aperture were used to describe the wavefront aberrations and to predict the initial state for the adaptive optics corrections.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Jan 01 2013
Journal Name
Iraqi Journal Of Physics
Describing the Wavefront Aberrations of the Hexagonal Aperture Using Modified Zernike Polynomials

n Segmented Optical Telescope (NGST) with hexagonal segment of spherical primary mirror can provide a 3 arc minutes field of view. Extremely Large Telescopes (ELT) in the 100m dimension would have such unprecedented scientific effectiveness that their construction would constitute a milestone comparable to that of the invention of the telescope itself and provide a truly revolutionary insight into the universe. The scientific case and the conceptual feasibility of giant filled aperture telescopes was our interested. Investigating the requirements of these imply for possible technical options in the case of a 100m telescope. For this telescope the considerable interest is the correction of the optical aberrations for the coming wavefront, th

... Show More
Publication Date
Sun Jan 16 2022
Journal Name
Iraqi Journal Of Science
Simulations of Four Types of Optical Aberrations using Zernik Polynomials

In this paper, a computer simulation is implemented to generate of an optical aberration by means of Zernike polynomials. Defocus, astigmatism, coma, and spherical Zernike aberrations were simulated in a subroutine using MATLAB function and applied as a phase error in the aperture function of an imaging system. The studying demonstrated that the Point Spread Function (PSF) and Modulation Transfer Function (MTF) have been affected by these optical aberrations. Areas under MTF for different radii of the aperture of imaging system have been computed to assess the quality and efficiency of optical imaging systems. Phase conjugation of these types aberration has been utilized in order to correct a distorted wavefront. The results showed that

... Show More
View Publication Preview PDF
Publication Date
Sat Jul 31 2021
Journal Name
Iraqi Journal Of Science
Computer Simulation for the Effects of Optical Aberrations on Solar Images Using Karhunen-Loeve polynomials

     Numerical simulations were carried out to evaluate the effects of different aberrations modes on the performance of optical system, when observing and imaging the solar surface. Karhunen-Loeve aberrations modes were simulated as a wave front error in the aperture function of the optical system. To identify and apply the appropriate rectification that removes or reduces various types of aberration, their attribute must be firstly determined and quantitatively described. Wave aberration function is well suitable for this purpose because it fully characterizes the progressive effect of the optical system on the wave front passing through the aperture. The Karhunen-Loeve polynomials for circular aperture were used to

... Show More
Scopus (3)
Crossref (2)
Scopus Crossref
View Publication Preview PDF
Publication Date
Sat Sep 23 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Zernike Polynomiales· for Opticl Ssytew. With Borizantal Recta_nguJar Aperture

For  small   aberrations,  the  Â·suehl'  ratio of  an . im i'ng syStem

  • depends on trne aberration v·ariance. Its· aberration fu.nct1on ·is e:qJanded in terms 9f-l nike polynomials. which are_ oirrh6goilal over a circular apeltitte. Their advane Uejn the    f;:l t tbat they call be icl.eritified. witl·c1a:s.sh::aj. abe,ttati{)ns 'balanced to jield  minimum varia,.o_q,and

thuS maximum St:rehl  t"a;tio. [n r«enr pap-er, we derived Cl<lse4 .fonn or

Zmike   polyhotnials  that  ate  orthonormal  over "- horizontal rect'angul'ar pupil'. (p.anil.lel to· the >Htxi.es) with ar'€

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
Generalized Schultz and Modified Schultz Polynomials for Some Special Graphs

With simple and undirected connected graph Φ, the Schultz and modified Schultz polynomials are defined as  and , respectively, where the summation is taken over all unordered pairs of distinct vertices in V(Φ), where V(Φ) is the vertex set of Φ, degu  is the degree of vertex u and d(v,u) is the ordinary distance between v and u, u≠v. In this study, the Shultz distance, modified Schultz distance, the polynomial, index, and average for both have been generalized, and this generalization has been applied  to some special graphs.

Scopus Crossref
View Publication Preview PDF
Publication Date
Thu Jun 20 2019
Journal Name
Baghdad Science Journal
A Comparative Analysis of the Zernike Moments for Single Object Retrieval

Zernike Moments has been popularly used in many shape-based image retrieval studies due to its powerful shape representation. However its strength and weaknesses have not been clearly highlighted in the previous studies. Thus, its powerful shape representation could not be fully utilized. In this paper, a method to fully capture the shape representation properties of Zernike Moments is implemented and tested on a single object for binary and grey level images. The proposed method works by determining the boundary of the shape object and then resizing the object shape to the boundary of the image. Three case studies were made. Case 1 is the Zernike Moments implementation on the original shape object image. In Case 2, the centroid of the s

... Show More
Crossref (2)
Clarivate Crossref
View Publication Preview PDF
Publication Date
Fri Apr 02 2021
Journal Name
New Trends In Information And Communications Technology Applications: 4th International Conference, Ntict 2020, Baghdad, Iraq, June 15, 2020, Proceedings 4
Publication Date
Sun Apr 26 2020
Journal Name
Iraqi Journal Of Science
The Numerical Approximation of the Bioheat Equation of Space-Fractional Type Using Shifted Fractional Legendre Polynomials

The aim of this paper is to employ the fractional shifted Legendre polynomials (FSLPs) in the matrix form to approximate the fractional derivatives and find the numerical solutions of the one-dimensional space-fractional bioheat equation (SFBHE). The Caputo formula was utilized to approximate the fractional derivative. The proposed methodology applied for two examples showed its usefulness and efficiency. The numerical results showed that the utilized technique is very efficacious with high accuracy and good convergence.

Scopus (3)
Crossref (2)
Scopus Crossref
View Publication Preview PDF
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
View Publication Preview PDF
Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Computational And Theoretical Nanoscience
Scopus (5)
Crossref (7)
Scopus Crossref
View Publication