mExamine1

Usage

Overview

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]