NAME

       mExec - Create a 2MASS, SDSS or DSS mosaic based on a size and location

SYNOPSIS

       mExec  [-q] [-r rawdir] [-n ntilex] [-m ntiley] [-l] [-k] [-c] [-o output.fits] [-d level]
       [-f region.hdr | -h header] survey band [workspace-dir]

DESCRIPTION

       The mExec module is a mosaicking executive for 2MASS, SDSS, and  DSS  data.   It  includes
       remote data and metadata access.  Alternatively, users can mosaic a set of data already on
       disk.

OPTIONS

       -q     Use mProjectQL for reprojections.  Much faster but not quite flux-conserving.

       -r rawdir
              Provide  path  to  directory  containing  original  ("raw")  data  which  will   be
              reprojected  and  mosaicked.   Not necessary if using mExec to retrieve remote data
              from the 2MASS, SDSS or DSS surveys.

       -n ntilex
              Number of output tiles to create along the X-axis -  default  is  1  for  a  single
              mosaicked image.

       -m ntiley
              Number of output tiles to create along the Y-axis - default is equal to ntilex.

       -l     "Level-only" flag (see mBgModel)

       -k     If  retrieving  data from a remote archive, the "keep" flag will leave the original
              data products on disk after generating a mosaic.  Without this flag, raw data  will
              be deleted (unless it was provided by the user with the "-r" flag).

       -c     Remove  all temporary files and intermediate data products.  Note: if not using the
              '-o' flag to specify an output file, this will also remove mosaic.fits.

       -o output.fits
              Provide  your  own  filename  for  the  output   mosaic.    Default   filename   is
              "mosaic.fits."

       -d level
              Print out additional debugging information (levels 1-4)

ARGUMENTS

       mExec  must be provided with FITS header information.  This can be in the form of a header
       template ("-f" flag), or the user can pass header  text  directly  to  the  program  ("-h"
       flag).

       -f region.hdr
              Path to header template used to create mosaic.

       -h header

              Provide header template as text input rather than point to a file; see sample shell
              script that makes use of this option.

       survey band
              If not mosaicking user-provided data ("-r" flag), must select one of the  following
              combinations of survey and band:

              2MASS  [j,  h, k] SDSS [u, g, r, i, z] DSS [DSS1, DSS1R, DSS1B, DSS2, DSS2B, DSS2R,
              DSS2IR]

       workspace-dir
              Directory where intermediate files will be created.  If no workspace  is  given,  a
              unique local subdirectory will be created (e.g.; ./MOSAIC_AAAaa17v)

RESULT

       [struct stat="OK", workspace="workspace-dir"]

       The  output  mosaic(s), and any intermediate files (if the "-c" flag was not used) will be
       inside workspace-dir.

MESSAGES

       OK     [struct stat="OK", workspace="workdir"]

       ERROR  Must have either header file (-f) or header text (-h)

       ERROR  Can't open original header template file: [region.hdr]

       ERROR  Can't open workspace header template file: [region.hdr]

       ERROR  Can't create proper subdirectories in workspace (may already exist)

       ERROR  Can't open header template file

       ERROR  Can't open expanded header file: [big_region.hdr]

       ERROR  survey has no data covering expanded area

       ERROR  survey has no data covering this area

       ERROR  No data was available for the region specified at this time

       ERROR  Bad WCS in input image

       ERROR  Can't open mosaic file: [mosaic.fits]

       ERROR  Can't open save file: [image.fits]

       ERROR  Output wcsinit() failed

       ERROR  Error from another Montage module

EXAMPLES

       To create a small mosaic  of  the  area  around  m31,  located  at  coordinates  "10.68469
       41.26904":

       $ mHdr m31 0.3 m31.hdr
              [struct stat="OK", count="16"]

       $ mExec -o m31.fits -f m31.hdr 2MASS J tempdir
              [struct stat="OK", workspace="/path/to/tempdir"]

       To mosaic your own collection of data, contained in the directory "raw":

       $ mImgtbl raw raw.tbl
              [struct stat="OK", count=16, badfits=0]

       $ mMakeHdr raw.tbl raw.hdr

              [struct   stat="OK",   count=16,  clon=0.118289,  clat=0.118288,  lonsize=0.236660,
              latsize=0.236660,      posang=359.999756,      lon1=0.236618,       lat1=-0.000042,
              lon2=359.999959,  lat2=-0.000041,  lon3=359.999959,  lat3=0.236618,  lon4=0.236620,
              lat4=0.236617]

       $ mExec -o my_mosaic.fits raw.hdr workdir
              [struct stat="OK", workspace="/path/to/workdir"]

BUGS

       The drizzle algorithm has been implemented but has not been tested in this release.

       If a header template contains  carriage  returns  (i.e.,  created/modified  on  a  Windows
       machine),  the cfitsio library will be unable to read it properly, resulting in the error:
       [struct stat="ERROR", status=207, msg="illegal character in keyword"]

       It is best for the background correction algorithms if the area described  in  the  header
       template  completely encloses all of the input images in their entirety. If parts of input
       images are "chopped off" by  the  header  template,  the  background  correction  will  be
       affected.  We  recommend  you  use  an expanded header for the reprojection and background
       modeling steps, returning to the originally desired header size for the final  coaddition.
       The default background matching assumes that there are no non-linear background variations
       in the individual images (and therefore in the  overlap  differences).  If  there  is  any
       uncertainty  in  this  regard, it is safer to turn on the "level only" background matching
       (the "-l" flag in mBgModel.

COPYRIGHT

       2001-2015 California Institute of Technology, Pasadena, California

       If your research  uses  Montage,  please  include  the  following  acknowledgement:  "This
       research  made use of Montage. It is funded by the National Science Foundation under Grant
       Number ACI-1440620, and was previously  funded  by  the  National  Aeronautics  and  Space
       Administration's  Earth Science Technology Office, Computation Technologies Project, under
       Cooperative Agreement Number  NCC5-626  between  NASA  and  the  California  Institute  of
       Technology."

       The  Montage  distribution  includes an adaptation of the MOPEX algorithm developed at the
       Spitzer Science Center.