Relation between the quantity of sampled stars and the ePSF modes accuracy in Astrometry
Effective point-spread function(ePSF) method is an excellent method for the positional measurements of stars in undersampled stellar images, whose critical step is deriving an accurate ePSF mode. In the presentation, we investigate the effects of the grid density and the sample density on the modes accuracy through some experiments on positional measurement in synthetic undersampled stellar images. We find that constructing a stable ePSF mode requires two samples in every cell (basic unit of pixel segmentation) for a certain grid. That is, ideally, 2n2 sampled stars in a stellar image are enough for constructing a stable ePSF mode. Whether the derived stable ePSF mode is accurate is related to the grid density, the denser the modes grid is, the more accurate it is.
effective point-spread function PSF mode undersampled Image positional measurement astrometry
Zhang Qing-feng He Hai-feng PengQing-yu ZhuZi
Joint Laboratory for Astrometry, Dynamics and Space Science, Jinan University, Guangzhou, China Key Joint Laboratory for Astrometry, Dynamics and Space Science, Jinan University, Guangzhou, China Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nan
国际会议
重庆
英文
426-429
2011-01-21（万方平台首次上网日期，不代表论文的发表时间）