Name

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    XY2SKY

Purpose

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    Converts between pixel coordinates of a FITS image and sky coordinates
    using the WCSTOOLS xy2sky routine. Useful for images with WCS keywords
    that are not implemented in the astronomy library (such as the TNX
    convention for distortions).

Category

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    Astro

Calling Sequence

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    Result = XY2SKY(FITSFile, X, Y)

Inputs

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    FITSFile: Name of FITS file that contains the WCS to use.
    X: Vector of x coordinates.
    Y: Vector of y coordinates.

Keyword Parameters

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    STRING: Output strings of HH:MM:SS and DD:MM:SS format.
    WCSTOOLSDIR: Path to the location of the binary xy2sky in wcstools.

Outputs

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    The function returns a structure with fields .RA and .DEC which are arrays
    containing the RA and Dec values in decimal degrees (or in strings,
    if /STRING is set).

Notes

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    Requires WCSTOOLS to be installed, along with the UWashington TMPFILE
    and DIR_EXIST routines.

Modification History

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    Written by: Jeremy Bailin
    20 August 2010 Initial release
    10 Feb 2011 Made WCSTOOLSDIR a keyword parameter.