XMM-Newton Science Analysis System


ecoordconv (especget-1.39.2) [xmmsas_20141104_1833-14.0.0]

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Description

This task converts a position in an image from one coordinate system into positions in other coordinate systems. For example the routine can be used to convert a celestial sky position (RA, DEC) into detector coordinatesi (DETX, DETY), chip coordinates (RAWX, RAWY), X/Y pixels and TelCoords (theta, phi). It also gives the numbers of the CCDs which are included within an input region.

Note that the conversion technique moves the input position to the centre of the image pixel containing that position. This gives the slightly strange result that the output coordinates, while being consistent with each other, are not exactly the same as the input position. Obviously the finer the binning of the input image the closer will be the correspondance between the input and the output values.

Table 1: Output quantities

Value	Units	Units
Theta	Off-axis angle	arc seconds
Phi	Azimuthal angle	Radians
X	X sky coord	0.05 arcsec pixel
Y	Y sky coord	0.05 arcsec pixel
DETX	Detector X coord	0.05 arcsec pixel
DETY	Detector Y coord	0.05 arcsec pixel
RA	Right ascension	degrees
DEC	Declination	degrees
RAWX	X chip coordinate	pixel
RAWY	Y chip coordinate	pixel
CCD(s)	CCD number(s) in region	-
Central CCD	CCD at region centre	-