There are several atmospheric phenomena affecting astronomical observations. Passing through atmosphere some part of light is absorbed by atmosphere. Turbulence in the atmosphere makes light beams deviate from straight line. These phenomena cause to distortions in images, obtained by astronomical observations. Some of them depend on weather, and other depends on location of site of observations. For accurate optical measuring we need to know errors and take them into account. If these errors are too large, we need to choose another place for observations.
We need to estimate these basic parameters of astronomical seeing:
– light absorption in atmosphere;
– image blurring;
– image vibration and scintillation;
– background atmospheric glow.
If these parameters are significant, penetrating ability of telescope decreases and errors in measuring angular coordinates increase.
All these parameters could be estimated by processing images of stars. Coordinates, brightness and temperature of stars are measured well enough. And their angular sizes are so small, so we could consider them as point objects. Brightness calculated from catalogue data and brightness measured by photosensor could be used for estimating light absorption in atmosphere. Image blurring could be estimated as size of star image. A sequence of images of star pattern is supposed to be used for estimating image vibration and scintillation. And we can calculate background atmospheric glow from data obtained in previous calculations.
The program estimating following parameters was developed:
– Background atmospheric glow;
– Image blurring;
– Image vibration and scintillation.