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: http://xmm.vilspa.esa.es/sas/7.1.0/doc/omdetect/node8.html
Дата изменения: Mon Jul 9 06:34:53 2007 Дата индексирования: Sat Dec 22 09:52:38 2007 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п |
subroutine omdetect read data for selected OSW image get mode of image by sigma clipping to get average background level Loop though all pixels on the image- for each pixel with a value >=nsigma * background mode analyse surrounding pixels to ascertain if these pixels may constitute a ``point'' source. If so, set the pixels to an assigned source number, compute the source position and shape by moments, and store the parameters. Repeat until all pixels have been checked. Recompute the background mode, ignoring those pixels assigned to a point-source. Check all the remaining pixels and those with a value >=nsigma * background mode assign a number. Analyse these pixels for individual extended sources and assign a number to each one. Compute the source position and shapes of each extended source by moments, and store the parameters. Perform aperture photometry on each source. Examine each point-source and discard any with a significance less than the minimum allowed value. Examine each extended source to attempt to see if it is just scattered light around a point-source- reject this source if it is. write output sourcelist containing source parameters. Also output detection count rate threshold. end subroutine omdetect