Provided by: montage_6.0+dfsg-6build3_amd64 
NAME
mProjectPP - Re-project FITS images
SYNOPSIS
mProjectPP [-z factor] [-d level] [-b border] [-s statusfile] [-o altout.hdr] [-i
altin.hdr] [-h hdu] [-x scale] [-w weightfile] [-W fixed-weight] [-t threshold] [-X] [-b
border-string] in.fits out.fits template.hdr
DESCRIPTION
mProjectPP reprojects a single image to the scale defined in an alternate FITS header
template generated (usually) by mTANhdr. 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. This area image goes through all the subsequent processing
that the reprojected image does, allowing it to be properly coadded at the end.
mProjectPP performs a plane-to-plane transform on the input image, and is an adaptation of
the Mopex algorithm and developed in collaboration with the Spitzer Space Telescope. It
provides a speed increase of approximately a factor of 30 over the general-purpose
mProject. However, mProjectPP is only suitable for projections which can be approximated
by tangent-plane projections (TAN, SIN, ZEA, STG, ARC), and is therefore not suited for
images covering large portions of the sky. Also note that it does not directly support
changes in coordinate system (i.e. equatorial to galactic coordinates), though these
changes can be facilitated by the use of an alternate header.
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 levels greater than 1, it's recommended to redirect the output into a text
file.
-b border
Ignores border pixels around the image edge when performing calculations.
-s statusfile
Output and errors are written to statusfile instead of being written to stdout.
-[i|o] alternate.hdr
Specifies an alternate FITS header for use in mProjectPP calculations, allows
substitution of psuedo-TAN headers created by mTANHdr.
-h hdu Specify the FITS extension to re-project if the FITS image is multi-extension.
-x scale
Multiple the pixel values by scale when reprojecting. For instance, each 2MASS
image has a different scale factor (very near 1.0) to correct for varying
magnitude-zero points.
-w weightfile
Path to a weight map to be used when reading values from the input image.
-W fixed-weight
Use constant weight value for the whole 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
-b border-string
Define a border width or border pixel corners outside of which all pixels are set
to NaN.
ARGUMENTS
in.fits
Input FITS file to be reprojected.
out.fits
Path to output FITS file to be created.
template.hdr
FITS header template to be used in generation of output FITS
RESULT
Two files are created as output: the reprojected FITS file (out.fits), and an "area" image
(out_area.fits). See the image reprojection algorithm for more information.
MESSAGES
OK [struct stat="OK", time=seconds]
ERROR Drizzle factor string (string) cannot be interpreted as a real number
ERROR Cannot open status file: statusfile
ERROR Weight threshold string (threshold) cannot be interpreted as a real number
ERROR Flux scale string (scale) cannot be interpreted as a real number
ERROR Border value string (string) cannot be interprted as an integer or a set of polygon
vertices
ERROR Border value (value) must be greater than or equal to zero
ERROR HDU value (hdu) must be a non-negative integer
ERROR Could not set up plane-to-plane transform. Check for compliant headers.
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 Input and output must be in the same coordinate system for fast reprojection
ERROR All pixels are blank
ERROR Input image projection (projection) must be TAN, SIN, ZEA, STG or ARC for fast
reprojection
ERROR Output image projection (projection) must be TAN, SIN, ZEA, STG or ARC for fast
reprojection
ERROR Template file [template.hdr] not found
ERROR Image file in.fits is missing or invalid FITS
ERROR Weight file weightfile is missing or invalid FITS
ERROR FITS library error
EXAMPLES
$ mProjectPP rawdir/real_orig.fits projdir/base_unity.fits templates/galactic_orig.txt
[struct stat="OK", time=14]
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.
mProjectPP is only suitable for use on projections which can be approximated by tangent-
plane projections (TAN, SIN, ZEA, STG, ARC), and is therefore not suited for images
covering large portions of the sky. Also note that it does not directly support changes in
coordinate system (i.e. equatorial to galactic coordinates), though these changes can be
facilitated by the use of an alternate header.
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.