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оригинального документа
: http://xmm.vilspa.esa.es/sas/7.0.0/doc/movecalc/node3.html
Дата изменения: Wed Jun 28 23:25:18 2006 Дата индексирования: Sat Dec 22 09:31:03 2007 Кодировка: Поисковые слова: x-ray background |
movecalc takes an event table with aspect corrected X/Y coordinate columns (as generated by task attcalc) and adds two new columns X_MOV/Y_MOV (different names can be specified via parameters xmovcol/ymovcol) containing the corresponding coordinates in a reference frame that is centered on the moving object at all times. This requires a second input table which defines the track of the object as a function of time. The table is created with the task iauephem and passed to movecalc via the parameter objtrack. movecalc shall interpolate the object tracking data in time on an event by event basis. This requires access to the event arrival times in a column TIME by default.
The new X_MOV/Y_MOV coordinate system is characterized by the following properties:
Please note: Geocentric parallax shifts are taken into account. This refers to the fact that the apparent direction from the satellite to the object does in general not coincide with its geocentric position vector. The effect is the bigger the closer the object is.