mTANHdr - Determine if there would be an equivalent distorted TAN projection

       orig.hdr
              Input FITS header

       new.hdr
              Path to output header to be created

       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.

       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.

Montage 5                                           Dec 2016                                          MTANHDR(1)

       Analyzes  a  template  file  and  determines  if  there  would  be  an  adequate equivalent distorted TAN
       projection, within a specified tolerance, and outputs the alternate header. This header can  be  used  in
       conjunction  with  mProjectPP  to  produce  a  TAN  plane image. This process is considerably faster than
       projecting with the general purpose tool mProject.

       The output header is a FITS header template containing a  TAN  projection  with  polynomial  focal  plane
       distortions. (Link to an example output header)

       mTANHdr  is  most  suitable  for projections which can be approximated by tangent-plane projections (TAN,
       SIN, ZEA, STG, ARC), and is also therefore not suited for images covering large portions of the sky.

       $ mTANHdr input/SIN_1.hdr alternate.hdr
              [struct   stat="OK",  fwdxerr=4.31068e-05,  fwdyerr=4.42599e-05,  fwditer=4,  revxerr=1.22123e-05,
              revyerr=1.19694e-05, reviter=4]

       The output header is a FITS header template containing a  TAN  projection  with  polynomial  focal  plane
       distortions: alternate.hdr

       OK     [struct    stat="OK",    fwdxerr=fwdxerr,    fwdyerr=fwdyerr,    fwditer=iter,    revxerr=revxerr,
              revyerr=revyerr, reviter=reviter]

       ERROR  -i (iterations) argument

       ERROR  -o (order) argument

       ERROR  -t (tolerance) argument

       ERROR  Cannot open status file: statusfile

       ERROR  Cannot open output template file new.hdr

       ERROR  All points offscale in forward transform

       ERROR  All points offscale in reverse transform

       ERROR  Bad template: orig.hdr

       ERROR  Output wcsinit() failed.

       ERROR  Singular Matrix-1

       ERROR  Singular Matrix-2

       ERROR  Allocation failure in ivector()

       mTANHdr - Determine if there would be an equivalent distorted TAN projection

       -d     Print additional debugging information to stdout.

       -o order
              Order of output header polynomial focal plane distortions (default = 4)

       -i maxiter
              Maximum number of iteration attempts to produce header (default = 50)

       -t tolerance
              Distortion tolerance value for acceptable output (default = 0.01)

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

[structstat="OK",fwdxerr=fwdxerr,fwdyerr=fwdyerr,fwditer=iter,revxerr=revxerr,revyerr=revyerr,reviter=reviter]

       where  fwdxerr and fwdyerr are the maximum errors along each axis found when projecting from the original
       image to the distorted header; revxerr and revyerr are the maximum errors  along  each  axis  found  when
       projecting  from the distorted header back to the original header; and fwditer and reviter are the number
       of iterations required in each direction to converge on a solution.

       mTANHdr [-d] [-o order][-i maxiter][-t tolerance][-s statusfile] orig.hdr new.hdr