.help XRSIMAGE Jun99 ASTROE
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NAME
xrsimage -- make "smoothed pixel" Astro-E XRS images

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USAGE
xrsimage  image_type event_file

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DESCRIPTION
This tool creates DET, FOC or sky (X/Y) images for the the Astro-E XRS 
instrument. Note that the XRS detector pixels are much larger than the 
image (DET, FOC or sky coordinate) pixels. For a given event file this tool
increments each image pixel lying under the XRS pixel by one. The effect is 
to distribute each event smoothly over the entire pixel. 

The resulting images are in units of counts. If you prefer
images in counts per image pixel, then you should use the "fcarith" FTOOL
to divide by the number of image pixels per XRS pixel.

Xrsimage will first try to read the values of the ra, dec, 
aberration, and follow_sun parameters from the event file header.
If the corresponding FITS keywords are not present it will read
values through the parameter interface. This way the coordinate calculations
done by xrsimage will be identical to the ones done by a previous coordinator
run, though the coordinator does not have to be run before xrsimage.


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PARAMETERS
.ls image_type [string]
In which type of coordinate should the image be created? Choices are
"DET", "FOC", or "SKY". DET coordinates are specific to the detector.
FOC coordinates are aligned such that they may be overlayed with XIS images,
and SKY images are in RA and Dec.
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.ls eventfile [string]
Name of the input FITS event file.
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.ls (eventext = "EVENT") [string]
Name of the FITS file extension containing the event list.
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.ls attfile [string]
Name of the attitude file needed for producing SKY images.
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.ls outfile [string]
Name of the output Image file.
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.ls teldef [string]
Name of the "Telescope Definition" calibration file.
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.ls (time_margin = 32.0) [real]
Limits for allowed extrapolation beyond the first or last rows of the attitude file in seconds. Events occuring outside this margin will be ignored.
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.ls ra [real]
This is the Right Ascension in decimal degrees of the point to appear
in the center of sky coordinate images.
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.ls dec  [real]
This is the Declination in decimal degrees of the point to appear
in the center of sky coordinate images.
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.ls (aberration = yes) [boolean]
Should the effects of abberation be taken into account when calculating
the sky coordinate values? Abberation is the apparent bending of light due
to the Earth's orbit around the Sun. This is at most a ~20 arc sec effect.
For normal use this parameter should be set to "yes".
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.ls (follow_sun = yes) [boolean]
Should abberation be recalculated for each event time? If set to "no" the
abberation at the time given by the "MJDOBS" keyword will be used for
all events. Setting this to "no" is acceptable except for very long 
observations and will make the program run slightly faster. 
The "yes" setting should be used for highest accuracy.
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EXAMPLES

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BUGS