IMSALT

Name

imsalt

Purpose (one Line Only)

Implants fake point-source images into an image of the sky.

Description

IMSALT will take four vectors of the same length (exten, x_pos, y_pos,
and scale) that describe the false objects to be put in FITS images
of real stars. These vectors are applied in order to insert psf(s)
of the appropriate parameters in the appropriate image(s) or extension.
IMSALT then writes a FITS file of the same name, with the false data
inserted. It is important to specify the paths of the input files
and/or the two output files, since SALTDES resists overwriting the
original data; it will not run if the name and path of the output is
the same as the input.

Calling Sequence

imsalt,imname,x_pos,y_pos,scale,exten

Inputs

imname :String, the name of the fits file to be read
x_pos :Vector, x locations on image
y_pos :Vector, y locations on image
mag :Vector, magnitude of fake objects
exten :Vector, chooses which extensions are to contain false
objects and how many in each. EX: exten=[1,1,7,5]

Optional Input Parameters

Keyword Input Parameters

KEYFILE - Name of a file containing a correspondence list. This list
associates a set of standard names with the actual keyword
names found in a FITS file header. If this keyword is
omitted, a default list is used, as if a file with the
following contents had been supplied:
AIRMASS K AIRMASS
DATE K DATE-OBS
DATETMPL T DD-MM-YYYY
EXPDELTA V 0.0
EXPTIME K EXPTIME
FILTER K FILTERS
FILENAME K CCDFNAME
OBJECT K OBJECT
UT K UT
The middle column is a flag. It may be K, for Keyword,
T, for Template, or V, for Value. If it is V, the contents
of the third field on that line should make sense for the
name in the first field.
IMDIR :String, the path to the original images- DEFAULT:current dir
PSFDIR :String, the path to the psfs- DEFAULT:SRCDIR+'/psf'
SRCDIR :String, the path to the src and srd files- DEFAULT:''
OUTDIR :String, set the path for the output data file. IMSALT
will not run if imdir=outdir - DEFAULT:'salted/'
NOPLOTS :Flag, if set suppresses plots of the data, the false
data, the salted data, and the data with 'colored salt.'
SALTFLAG :Flag, if set this to make a note in the header that the
file has been salted (add keyword SALTED=T)
QUIET :Flag, if set will suppress chatty printed output.

Outputs

Keyword Output Parameters

Side Effects

Restrictions

The inputs x_pos, y_pos, scale, and exten must have the same
length. Exten is used only with group FITS image files.
This program requires that PSFs be pre-generated from the images (see
PSFGEN.PRO). The psf files must adheare to the following restrictions.
The psfs must have the same basic format as the data files, meaning
that they must be multi-extension if the data files are multi-extension.
The psf header must contain the following information:
XCEN,YCEN - x and y location of the object on the psf
FWHM - fwhm of the object
MAX - peak pixel value of the psf
FLUX - flux from the psf in OBJRAD (also in psf header)
The psf name must be the same as the filename, except with a .psf appended
(replaces .fits tag if file name includes that).

Procedure

Modification History

2004/07/14, Written by Maureen Teyssier, REU Lowell Observatory
2004/07/15, MWB, incorporated into library.