天文研究与技术－国家天文台台刊
天文研究與技術－國傢天文檯檯刊
천문연구여기술－국가천문태태간
ASTRONOMICAL RESEARCH & TECHNOLOGY-PUBLICATIONS OF NATIONAL ASTRONOMICAL OBSERVATORIES OF CHINA
2010年
2期
132-139
,共8页
图像分析%星像%有效点扩散函数%高斯函数
圖像分析%星像%有效點擴散函數%高斯函數
도상분석%성상%유효점확산함수%고사함수
Image analysis%Stellar image%Effective point spread function%Gaussian functions
为了解决哈勃空间望远镜的图像欠采样问题,美国学者Anderson和King提出了精确测量星像位置和通量的有效点扩散函数(ePSF-effective point.spread function)拟合法.然而,他们却不加比较地将其应用于地面CCD图像中星像的位置高精度测量.因此,我们试图将ePSF拟合法与经典的高斯函数(Gaussian)拟合法作比较研究.调用CFITSIO库生成模拟的背景图像,并应用不同参数条件下的星像轮廓模型产生非欠采样的星像.最后,分别采用ePSF拟合法与Gaussian拟合法对这些星像进行拟合,并对它们的拟合精度进行比较.实验结果表明,在非欠采样的图像中这两种算法对星像位置的测量几乎是等精度的.
為瞭解決哈勃空間望遠鏡的圖像欠採樣問題,美國學者Anderson和King提齣瞭精確測量星像位置和通量的有效點擴散函數(ePSF-effective point.spread function)擬閤法.然而,他們卻不加比較地將其應用于地麵CCD圖像中星像的位置高精度測量.因此,我們試圖將ePSF擬閤法與經典的高斯函數(Gaussian)擬閤法作比較研究.調用CFITSIO庫生成模擬的揹景圖像,併應用不同參數條件下的星像輪廓模型產生非欠採樣的星像.最後,分彆採用ePSF擬閤法與Gaussian擬閤法對這些星像進行擬閤,併對它們的擬閤精度進行比較.實驗結果錶明,在非欠採樣的圖像中這兩種算法對星像位置的測量幾乎是等精度的.
위료해결합발공간망원경적도상흠채양문제,미국학자Anderson화King제출료정학측량성상위치화통량적유효점확산함수(ePSF-effective point.spread function)의합법.연이,타문각불가비교지장기응용우지면CCD도상중성상적위치고정도측량.인차,아문시도장ePSF의합법여경전적고사함수(Gaussian)의합법작비교연구.조용CFITSIO고생성모의적배경도상,병응용불동삼수조건하적성상륜곽모형산생비흠채양적성상.최후,분별채용ePSF의합법여Gaussian의합법대저사성상진행의합,병대타문적의합정도진행비교.실험결과표명,재비흠채양적도상중저량충산법대성상위치적측량궤호시등정도적.
In order to solve the problem of point spread function (PSF) undersampling for the images from the Hubble Space Telescope(HST),Anderson and King proposed an effective PSF model(ePSF) with which high-precision stellar positions and fluxes can be derived through fitting.However,they applied it to ground-based images without comparing with any classical methods.We thus compare fitting ePSF to the classical fitting with Gaussian functions.We used the CFITSIO Library to simulate background images,and superimpose simulated stellar images (not undersampled) corresponding to stellar profiles of different parameters on the background images.Finally,we fit ePSF and Gaussian functions to these stellar images separately,and make the comparison for their fitting precisions.The preliminary experiments show that the precisions of the positions measured with the two algorithms are nearly identical.
