Provided by: montage_4.0+dfsg-3_amd64 
NAME
mProject - Re-project FITS images
SYNOPSIS
mProject [-z factor] [-d level] [-s statusfile] [-h hdu] [-x scale] [-w weightfile] [-t threshold] [-X]
[-f] in.fits out.fits hdr.template
DESCRIPTION
mProject reprojects a single image to the scale defined in a FITS header template file (read more about
header templates here). The program produces a pair of images: the reprojected image and an "area" image
consisting of the fraction input pixel sky area that went into each output pixel. The "drizzle"
algorithm is implemented. The algorithm proceeds by mapping pixel corners (as adjusted by drizzle, if
called) from the input pixel space to the output pixel space, calculating overlap area with each output
pixel, and accumulating an appropriate fraction of the input flux into the output image pixels. In
addition, the appropriate fraction of the input pixel area is accumulated into the area image pixels.
Projection of points from input pixel space to output pixel space is calculated in two steps: first map
from input pixel space to sky coordinates; second map from sky coordinates to output pixel space.
One situation that has happened often enough to warrant special note: It is possible to define a FITS
header with the reference location off the image. In particular, people often reference cylindrical
projections (e.g., CAR, CEA) to location (0.,0.) (e.g., the Galactic center). This is not wrong in
itself but does lead to extremely large pixel offsets (e.g., in the hundreds of thousands). Related to
this, if you extract a header from an image with large offsets of this type, it is unlikely that you can
simply change projection types without also adjusting the reference location/offsets. Most likely, you
will end up with the reproject data all being off-scale.
OPTIONS
-z factor
Processing is done utilizing the drizzle algorithm. factor is a floating point number; recommended
drizzle factors are from 0.5 to 1.
-d level
Causes additional debugging information to be printed to stdout. Valid levels are 1-5 (for higher
debugging levels, it is recommended to redirect the output to a file).
-s statusfile
Output and errors are written to statusfile instead of being written to stdout.
-h hdu Use the specified FITS extension (default is to use the first HDU with image data)
-x scale
Apply a correction factor of scale to each pixel
-w weightfile
Path to a weight map to be used when reading values from the input image.
-t threshold
Pixels with weights below threshold will be treated as blank.
-X Makes the output region (originally defined in the header template) big enough to include all of
the input images
ARGUMENTS
in.fits
Input FITS file to be reprojected.
out.fits
Path of output FITS file to be created.
hdr.template
FITS header template to be used in generation of output image
RESULT
Two files are created as output: the reprojected FITS file (out.fits), and an "area" image
(out_area.fits) which records the amount of coverage (in output pixel space) provided by the input
images.
MESSAGES
OK [struct stat="OK", time=seconds]
ERROR Drizzle factor string (string) cannot be interpreted as a real number
ERROR Weight threshold string (string) cannot be interpreted as a real number
ERROR Flux scale string (string) cannot be interpreted as a real number
ERROR Cannot open status file: statusfile
ERROR HDU value (hdu) must be a non-negative integer
ERROR No overlap
ERROR Not enough memory for output data image array
ERROR Not enough memory for output area image array
ERROR Output wcsinit() failed.
ERROR Input wcsinit() failed.
ERROR FITS library error
ERROR All pixels are blank
ERROR Template file not found
ERROR Image file in.fits missing or invalid FITS
ERROR Weight file weightfile missing or invalid FITS
EXAMPLES
$ mProject rawdir/real_orig.fits projdir/base_unity.fits templates/galactic_orig.txt
[struct stat="OK", time=143]
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.