NAME

       mMakeHdr - Create a FITS header template for use in mosaic creation

SYNOPSIS

       MakeHdr  [-d  level]  [-s statusfile] [-p(ixel-scale) cdelt] [-P maxpixel] [-n] images.tbl
       template.hdr [system [equinox]]

DESCRIPTION

       From a list of images to be mosaicked together, mMakeHdr generates the  FITS  header  that
       best  describes  the output image.  If the input metadata represent a properly matched set
       of data cubes (three or four dimensions), the header will reflect this and can be used  in
       cube  mosaicking.   If  the  spatial  coverage  of  the  data  is  large enough that a TAN
       projection header is infeasable, an allsky (AITOFF) header will be  created,  though  this
       should  be  used  with  caution as it can easily be the result of metadata for images that
       shouldn't really be combined.

OPTIONS

       -d level
              Turns on debugging to the specified level (1-3).

       -s statusfile
              Output and errors are written to statusfile instead of to stdout.

       -p cdelt
              Specify a pixel scale for the header, if different from the input images.

       -P maxpixel
              Sanity check; forces an upper limit on derived NAXIS1, NAXIS2, just in time.

       -n     "North-aligned" flag.  By default, the FITS header generated  represents  the  best
              fit  to  the images, often resulting in a slight rotation.  If you want north to be
              straight up in your final mosaic, you should use this flag.

ARGUMENTS

       images.tbl
              Metadata table (generated by mImgtbl) describing the images to be mosaicked.

       template.hdr
              Path to header template to be generated.

       system (optional)
              Specifies the system for the header (default is Equatorial).  Possible values are:

              EQUJ EQUB ECLJ ECLB GAL SGAL

       equinox (optional)
              If a coordinate system is specified, the equinox can also  be  given  in  the  form
              YYYY.  Default is J2000.

RESULT

       Creation of output file template.hdr.

MESSAGES

       OK     [struct    stat   =   "OK",   count=nimages,   ncube=ncubes,   clon=ra,   clat=dec,
              lonsize=crpix1,  latsize=crpix2,   posang=ang,   lon1=ra1,   lat1=dec1,   lon2=ra2,
              lat2=dec2, lon3=ra3, lat3=dec3, lon4=ra4, lat4=dec4]

       OK     messages about projection and number of axes>

       ERROR  Memory allocation failure.

       ERROR  Invalid pixel scale string: cdelt

       ERROR  Cannot open status file: statusfile

       ERROR  Invalid system string.  Must be EQUJ|EQUB|ECLJ|ECLB|GAL|SGAL

       ERROR  Equinox string is not a number

       ERROR  Can't open output header file.

       ERROR  Invalid image metadata file: filename

       ERROR  Need  columns: ctype1 ctype2 nl ns crval1 crval2 crpix1 crpix2 cdelt1 cdelt2 crota2
              (equinox optional).  Four corners (equatorial) will be used if they exist  or  even
              just a single set of coordinates

       ERROR  Bad WCS for image n

       ERROR  Error computing boundaries.

       ERROR  Output wcsinit() failed.

EXAMPLES

       $ mMakeHdr 2mass-images.tbl orig.hdr
              [struct stat="OK", count=30]

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.

       Due  to  some  numerical approximation, the "North Up" bounding box calculated when the -n
       switch is on can be skewed a fraction of a degree.

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.