mExamine(1) Information about the sky coverage of a FITS image


  mExamine [-d][-p ra dec radius] image.fits


  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.


-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.


  Turn on debugging.



  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.


  If successful, returns the following:

       proj     Image projection 
       csys     Coordinate system 
       equinox  Coordinate system equinox 
       naxis    Number of axes in the file 
       naxis1   Image width (in pixels)
       naxis2   Image height 
       naxis3   Data cube depth (only if NAXIS > 2) 
       naxis4   Data cube fourth dimension (only if NAXIS > 3) 
       crval1   WCS reference coordinate for first axis 
       crval2   WCS reference coordinate for second axis 
       crpix1   Pixel value for reference coordinate 
       cdelt1   Pixel scale (degrees) 
       crota2   Rotation of image (E of N) 
       lonc     Sky coordinate of image center 
       ximgsize Image size (degrees) 
       rotequ   Rotation of image in Equatorial (J2000) 
       rac      Equatorial (J2000) coordinates of image center 
       ra1      Equatorial coordinates of four image corners 

   and optionally

       radius   Radius of pixel region (degrees) 
       radpix   Radius in pixels 
       npixel   Number of pixels in region 
       nnull    Number of null pixels 
       aveflux  Average flux for region 
       rmsflux  RMS of region fluxes 
       fluxref  Flux for reference location 
       sigmaref RMS of fluxes 
       xref     Pixel coordinates of reference location 
       raref    Equatorial (J2000) coordinated of reference location 
       fluxmin  Same for pixel with minimum flux 
       fluxmax  Same for pixel with maximum flux 

   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.


No ra, dec, radius location given or file name missing
File name missing
Cannot open FITS file test.fits
Cannot find WCS keys in FITS file test.fits
WCS initialization failed.
Location off the image.
Error reading FITS data.


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]


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.