High Precision Measurement Based On E-PSF Of Multi-Image

With the development of science and technology, there are more measurement techniques, so people get lots of observatory data. CCD as an important optoelectronic coupled devices, plays a more and more important role in optical image of non-contact measurement. CCD has become the main terminal for receiving telescope equipment, it is very important to extract the position and magnitude of star from CCD image for astronomical research. It is always a concern to how to improve CCD image processing method to improve the precision, it has great significance to research that.The image fusion as well as high-precision measurement method is applied to astronomical image processing, the processing with the final image can get the effective point spread function, and the star's position and brightness information can be reached by the e-PSF fitting astrology. The mean precision of x directions was 0.036 pixels, the mean precision of y directions was 0.044 pixel, the mean Photometry precision was 0.032mag.The measurement results show the effectiveness of the algorithm.In this paper, the comparison research of Photometry on the bright stars and dark stars using e-PSF(effective-Point-Spread-Function) and Gaussian function were described in detail. The stars in the 16 CCD images observed by National Astronomical 1 m telescope are divided into two types of light stars and dark stars according to the average luminosity, each of the e-PSF was Calculated and used to measure the stars. The results revealed that the precision is higher to use the e-PSF of bright stars to measure bright stars, and the precision is higher to use the Gauss-fitting to measure dark stars. The e-PSF has obvious advantages to measure the precision of bright stars, and the Gauss-fitting is better for dark stars.It shows that the morphological structure of the dark star is closer to Gaussian distribution.