Документ взят из кэша поисковой машины. Адрес оригинального документа : http://xmm.vilspa.esa.es/sas/5.4.1/doc/arfgen/node36.html
Дата изменения: Fri Jan 10 23:25:53 2003
Дата индексирования: Sat Dec 22 08:21:01 2007
Кодировка:
Поисковые слова: annular

XMM-Newton Science Analysis System


arfgen (arfgen-1.54.7) [xmmsas_20030110_1802-5.4.1]

Meta Index / Home Page / Algorithm

Encircled Energy Correction

• Rebin the energy grid used in the main stage by a factor eegridfactor

• For each energy

  if source box is circular or annular:

  • Calculate the enclosed fraction for this box radius ,off-axis angle and energy.

  if source box is non-circular:

  • Generate a model of the PSF centred at [xdet,ydet].

  • Loop over each pixel in filtered detector map, calculating PSF contribution in every cell. Add cell contribution to running total. This gives fraction of PSF within selected region for given energy

  • Write encircled energy fraction as an element of an encircled energy fraction vector.

• Interpolate EE fraction vector to map to original energy grid used in main stage.

• Divide area vector by EE fraction vector.