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Дата изменения: Wed Jul 2 03:32:34 2008
Дата индексирования: Fri Sep 5 18:32:16 2008
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Поисковые слова: elliptical galaxy

XMM-Newton Science Analysis System


attmove (attmove-1.5) [xmmsas_20080701_1801-8.0.0]

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Description

attmove is a utility task for use in the aid of analysis of moving targets (planets, comets etc). It is based on an algorithm devied by Pedro Rodriguez (prodrigu@xmm.vilspa.esa.es).

In contrast to movecalc, attmove creates a new Attitude History derived from an existing AHF, using a second input table which defines the track of the object as a function of time.

attmove uses selects an arbitrary reference pointing (currently calculated from the object track) and recalculates the attitude of the spacecraft (the VIEWRA and VIEWDECL entries in the AHF) according to the following formula:

$V^{t} = V_{ref} + (V^{t}_{ahf} - V^{t}_{obj})$

Where $V^{t}$ is the output attitude, $V_{ref}$ is the reference attitude, $V^{t}_{ahf}$ is the spacecraft attitude in the source AHF at time $t$ and $V^{t}_{ahf}$ is the coordinates of the target object at time $t$, corrected for Geocentric parallax.