Changes to the ARTDATA Package: Version 1.1

Since the first release of the ARTDATA package with V2.9 there have been
several bugs found and documented, as is natural, and some new features
and tasks have been added.  This note summarizes these changes.

The bugs (log numbers 127, 130, 131, and 135) are all in the main task
MKOBJECTS.  Two of these concern the size of the PSF as specified by
the "radius" parameter.  The radius parameter for the gaussian PSF
is interpreted as a FWHM instead of the intended HWHM (radius at half
maximum).  This leads to very narrow stars until one compensates for the
error.  The size of the moffat PSF are off by a small factor (~10%)
depending on the beta parameter.  Another bug causes objects near the edge
to be off by 1 pixel from the specified coordinates.  The last bug
prevents use of a user supplied profile function for the PSF.  A
distributed patch for the above problems is planned.  Thanks go to
Lindsey Davis and Steven Perry for the careful studies which identified
the first three bugs.

The artificial one dimensional spectra produced by MK1DSPEC have new
parameters allowing addition of a velocity shift specified either as
a velocity or redshift.  This is a useful addition for tests of radial
velocity programs.

The initial version of the package provided minimal headers; mostly
just the wavelengths for 1D spectra and the dispersion axis for 2D
spectra.  People then need to HEDIT keywords to make the images
work well with some packages.  Four things have been done to
make useful headers for the artificial data.  First, a detailed
log of parameters used to generate the images is included as COMMENT
cards.  This includes task parameters and information from data files
such as those in the star and galaxy list files produced by
STARLIST and GALLIST.  Second, the gain, read noise, exposure
time, and dispersion correction flag have been added to the header
when appropriate.  Third, each task has a new parameter for specifying
a header keyword data file containing a list of keywords and values
to be automatically added.  A default file is supplied but any set
for a particular type of data may be substituted.  Finally, a new
task called MKHEADER has been added which applies header keyword
data files to images.

A new task called MKEXAMPLES has been added.  Given the name of an
example from a menu an image is created.  This task is intended to
provide examples for the ARTDATA package as well as test and
demonstration images for the various packages.  The initial menu
includes long slit and multifiber spectra, a globular cluster,
a star field, a galaxy field, and a galaxy cluster.  Additional
examples will be added as demonstrations and test procedures are
developed for various packages.