Provided by: montage_6.0+dfsg-6build3_amd64 
NAME
mExamine - Information about the sky coverage of a FITS image
SYNOPSIS
mExamine [-d][-p ra dec radius] image.fits
DESCRIPTION
mExamine returns information about the sky coverage of a FITS image (assuming WCS keywords
in the header) and optionally pixel statistics for a region in the image.
OPTIONS
-p ra dec radius
Return information about a region (central pixel value, min, max values and
location, etc.) Coordinates and radius are in degrees unless given a "p" suffix,
in which case they are in pixels.
-a ra dec
Returns a simple aperture photometry fit to a location. Cannot be used at the same
time as the -p option above. Also supports the "p" suffix rule from above.
-d
Turn on debugging.
ARGUMENTS
image.fits
FITS file to examine. If the file has multiple HDUs, you can add that to the file
name, e.g., "m51.fits[2]". If an HDU is a datacube, you can select a plane
("m51.fits[2][256]"). Even if there is a single HDU, you need to specify it if you
want to specify a cube plane ("m51.fits[0][512]"). Note that this syntax may
require quotes around the file name string to avoid confusing your shell.
RESULT
If successful, returns the following:
projImage projection csysCoordinate system equinoxCoordinate system equinox naxisNumber of
axes in the file naxis1Image width (in pixels) naxis2Image height naxis3Data cube depth
(only if NAXIS > 2) naxis4Data cube fourth dimension (only if NAXIS > 3) crval1WCS
reference coordinate for first axis crval2WCS reference coordinate for second axis
crpix1Pixel value for reference coordinate crpix2 cdelt1Pixel scale (degrees) cdelt2
crota2Rotation of image (E of N) loncSky coordinate of image center latc ximgsizeImage
size (degrees) yimgsize rotequRotation of image in Equatorial (J2000) racEquatorial
(J2000) coordinates of image center decc ra1Equatorial coordinates of four image corners
dec1 ra2 dec2 ra3 dec3 ra4 dec4
and optionally
radiusRadius of pixel region (degrees) radpixRadius in pixels npixelNumber of pixels in
region nnullNumber of null pixels avefluxAverage flux for region rmsfluxRMS of region
fluxes fluxrefFlux for reference location sigmarefRMS of fluxes xrefPixel coordinates of
reference location yref rarefEquatorial (J2000) coordinated of reference location decref
fluxminSame for pixel with minimum flux sigmamin xmin ymin ramin decmin fluxmaxSame for
pixel with maximum flux sigmamax xmax ymax ramax decmax
If you specify region that is all blank, npixel will be zero, nnull will be the total
number of pixel examined, and the flux related parameters will all be zero.
MESSAGES
ERROR No ra, dec, radius location given or file name missing
ERROR File name missing
ERROR Cannot open FITS file test.fits
ERROR Cannot find WCS keys in FITS file test.fits
ERROR WCS initialization failed.
ERROR Location off the image.
ERROR Error reading FITS data.
EXAMPLES
mExamine -p 202.5 47.0 0.01 aJ_asky_980527n0240232.fits
[struct stat="OK", proj="SIN", csys="EQUJ", equinox=2000.0, naxis1=512,
naxis2=1024, crval1=202.5213942, crval2=47.1131924, crpix1=256.5, crpix2=512.5,
cdelt1=0.0002778, cdelt2=0.0002778, crota2=0.0034, lonc=202.5213942,
latc=47.1134702, ximgsize=0.142222, yimgsize=0.142222, rotequ=0.0034,
rac=202.5213942, decc=47.1131924, ra1=202.6260252, dec1=46.9706487,
ra2=202.4171950, dec2=46.9706407, ra3=202.4166112, dec3=47.2553630,
ra4=202.6265617, dec4=47.2553710, radius=0.0100000, radpix=36.00, npixel=5476,
nnull=0, aveflux=136.807, rmsflux=0.853615, fluxref=137.3, sigmaref=0.578143,
xref=309, yref=105, raref=202.5000208, decref=46.9999951, fluxmin=135.042,
sigmamin=-2.06764, xmin=328, ymin=77, ramin=202.4922870, decmin=46.9922153,
fluxmax=152.299, sigmamax=18.1493, xmax=307, ymax=117, ramax=202.5008338,
decmax=47.0033286]
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.