This is the command mExamine that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
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.
-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:
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
crpix2
cdelt1 Pixel scale (degrees)
cdelt2
crota2 Rotation of image (E of N)
lonc Sky coordinate of image center
latc
ximgsize Image size (degrees)
yimgsize
rotequ Rotation of image in Equatorial (J2000)
rac Equatorial (J2000) coordinates of image center
decc
ra1 Equatorial coordinates of four image corners
dec1
ra2
dec2
ra3
dec3
ra4
dec4
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
yref
raref Equatorial (J2000) coordinated of reference location
decref
fluxmin Same for pixel with minimum flux
sigmamin
xmin
ymin
ramin
decmin
fluxmax Same 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]
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