We describe a new iteration method to estimate asteroid coordinates, which isbased on the subpixel Gaussian model of a discrete object image. The methodoperates by continuous parameters (asteroid coordinates) in a discreteobservational space (the set of pixels potential) of the CCD frame. In thismodel, a kind of the coordinate distribution of the photons hitting a pixel ofthe CCD frame is known a priori, while the associated parameters are determinedfrom a real digital object image. The developed method, being more flexible inadapting to any form of the object image, has a high measurement accuracy alongwith a low calculating complexity due to a maximum likelihood procedure, whichis implemented to obtain the best fit instead of a least-squares method andLevenberg-Marquardt algorithm for the minimisation of the quadratic form. Since 2010, the method was tested as the basis of our CoLiTec (CollectionLight Technology) software, which has been installed at several observatoriesof the world with the aim of automatic discoveries of asteroids and comets on aset of CCD frames. As the result, four comets (C/2010 X1 (Elenin), P/2011NO1(Elenin), C/2012 S1 (ISON), and P/2013 V3 (Nevski)) as well as more than1500 small Solar System bodies (including five NEOs, 21 Trojan asteroids ofJupiter, and one Centaur object) were discovered. We discuss these results thatallowed us to compare the accuracy parameters of a new method and confirm itsefficiency. In 2014, the CoLiTec software was recommended to all members of theGaia-FUN-SSO network for analysing observations as a tool to detect faintmoving objects in frames.
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