Image quality analysis for different atmosphere slant path Zenith angle

During the day, the ground usually becomes hot because of solar radiation. The lowest atmospheric layer absorbs heat from the ground, expands, and rises, producing the worst turbulence and atmosphere refractive change. This refractive index along the atmospheric path will produce an aberration in the image of the object and destroy the image quality at the image plane. The slant path refractive index in the atmosphere path is more complicated than the horizontal direction and need numerical methods to calculate it. In this work, the image quality for different slant path was studied. The effects of angle of observation (Zenith angle Z0=0, 5, 50, 60, 70, 80, and 90 degrees) on the image merit functions (Optical Path Difference (OPD)) are discussed in detail. It is shown that the result is sensitive to the range and angle of observation.