وفاء حكمت وديع
In this paper, the effect of the static aberration on the extended objects (satellite) has been studied when it was observed, that cause deviation or aberration of wavefront through lenses, causing blurred images of object. In an ideal system, every point on the object will focus to a point of zero size on the image. Practically, each image point occupies a volume of finite size and unsymmetrical shape, causing some blurring of the whole images. Those aberrations are generated by variations of the temperature and the inclination of the telescope tube. For telescopes the considerable interest is the correction of the optical aberrations for the coming wavefront, therefore, the Zernike polynomials for circular aperture were used to describe the wavefront aberrations. The results show that the most dominant effect on the quality of the optical system is the spherical aberration modes.