Документ взят из кэша поисковой машины. Адрес оригинального документа : http://xmm.vilspa.esa.es/sas/5.4.1/doc/embadpixfind/node6.html
Дата изменения: Fri Jan 10 22:54:27 2003
Дата индексирования: Sat Dec 22 13:10:33 2007
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Поисковые слова: полнолуние

XMM-Newton Science Analysis System


embadpixfind (embadpixfind-1.8) [xmmsas_20030110_1802-5.4.1]

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Dark pixels

If finddead=Y, embadpixfind looks for too dark pixels, rows and columns using the same algorithm (but reversed to look for holes). The statistics in a single observation is usually not enough to find any dark pixel, but dark rows or columns may be found. The maxratio parameter avoids detecting 'grey' pixels, rows or columns on observations with high statistics.

Whatever findbright, the very bright pixels/rows/columns (found at probathreshold squared) are looked for first (some are so bright that they can disrupt the more subtle row and column searches). If both findbright=Y and finddead=Y, dark columns, rows and pixels are looked for first and ignored in the search for bright pixels (at the normal probathreshold), columns and rows, to avoid underestimating the local median and average.