xenial (1) mFitplane.1.gz

Provided by: montage_4.0+dfsg-3_amd64 bug

NAME

       mFitplane - Use least squares to fit a plane to an image

SYNOPSIS

       mFitplane [-b border] [-d level] [-s statusfile] in.fits

DESCRIPTION

       Uses  least  squares  to fit a plane (excluding outlier pixels) to an image. It is used on the difference
       images generated using mDiff or mDiffExec.

OPTIONS

       -b border
              Number of border pixels to ignore at edges of image.

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

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

ARGUMENTS

       in.fits
              Input FITS file is a difference file between two other FITS  files,  as  can  be  generated  using
              mDiff.

RESULT

       The plane fit to the image is of the form:

         fit = A*x + B*y + C

       where  x  is  the "horizontal" pixel offset from CRPIX1 in the FITS header and y is the "vertical" offset
       from CRPIX2.  Since all reprojected images use the same reference pixel, this is a uniform definition for
       x,y for the whole image set.

       The  fitting is a simple least squares, with an iterative loop to exclude points more than 2 sigma (sigma
       defined as the rms from the previous loop).

       The rms output is the value computed above.  The xmin, ... ymax output correspond to  the  range  of  x,y
       values  found  while  fitting.   The  rms  is for information only but the xmin, ... ymax are used in the
       background fitting (mBgModel).  crpix1 and crpix2 are the reference pixels for each axis,  as  determined
       from the FITS header.

MESSAGES

       OK     [struct  stat="OK",  a=A, b=B, c=C, crpix1=crpix1, crpix2=crpix2, xmin=xmin, xmax=xmax, ymin=ymin,
              ymax=ymax,  xcenter=xcenter,  ycenter=ycenter,  npixel=npixel,  rms=rms,   boxx=boxx,   boxy=boxy,
              boxwidth=boxwidth, boxheight=boxheight, boxang=boxang]

       ERROR  Argument to -b (string) cannot be interpreted as an integer

       ERROR  Cannot open status file: statusfile

       ERROR  Image file filename missing or invalid FITS

       ERROR  FITS library error

       ERROR  general error

       WARNING
              Too few pixels to fit

       WARNING
              Too few pixels for bounding box

       WARNING
              Singular Matrix-1

       WARNING
              Singular Matrix-2

       WARNING
              allocation failure in ivector()

EXAMPLES

       $ mFitplane 2mass-atlas-990322n-j0640266.fits
              [struct   stat="OK",   a=-8.9198e-11,  b=-2.54173e-10,  c=5.24277e-05,  crpix1=808,  crpix2=212.5,
              xmin=-808, xmax=167, ymin=-210.5, ymax=638.5,  xcenter=-320.871,  ycenter=213.014,  npixel=314299,
              rms=0.393003, boxx=-320.92, boxy=212.424, boxwidth=835.421, boxheight=509.274, boxang=-29.5537]

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.

       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.