Документ взят из кэша поисковой машины. Адрес оригинального документа : http://xmm.vilspa.esa.es/calibration/documentation/CALHB/node915.html
Дата изменения: Tue Sep 20 19:45:21 2011
Дата индексирования: Mon Apr 11 03:36:43 2016
Кодировка:
Поисковые слова: hydrogen

Calibration Access and Data Handbook

Generation from Ground Calibration Data

In the CSL images there is clear evidence of edge emission. The area of edge emission has been flagged as bad pixels by

• co-adding all CSL images not degraded by the electronic problem
  file: rcslsummed.fits.gz
• computation of the average pixel value in the lower and upper left corner. (Note that the median in both areas was zero).
• flagging pixels as bad with an pixel content of greater equal two times the average value.

Pinhole images are almost free of any background and are not suitable to identify further defects.

Because of the problem in the OM electronics neither flatfield nor darkframe images were acquired at CSL. Although such measurements are available for the intensifier, these measurements are not directly usable, because they provide relative positional information only. I.e. these measurements are suitable to quantify defects, but not to derive their exact position. The CCD used in these measurements had an arbitrary location in respect to the intensifier. Two images were taken with the CCD rotated by 90 degree to distinguish between intensifier and CCD defects.

The relative position of identified defects to each other can be derived. Study is ongoing whether these defects can be found in the CSL image. In this case these pixels will be added to the badpix file.