mExamine
- 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.
- Syntax:
- mExamine [-d][-p ra dec radius] image.fits
Switches:
- -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.
- Results:
-
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.
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]
Return Codes:
- [struct stat="ERROR", msg="No ra, dec, radius location given or file name missing"]
- [struct stat="ERROR", msg="File name missing"]
- [struct stat="ERROR", msg="Usage: mExamine [-d][-p ra dec radius] image.fits"]
- [struct stat="ERROR", msg="Cannot open FITS file test.fits"]
- [struct stat="ERROR", msg="Cannot find WCS keys in FITS file test.fits"]
- [struct stat="ERROR", msg="WCS initialization failed."]
- [struct stat="ERROR", msg="Location off the image."]
- [struct stat="ERROR", msg="Error reading FITS data."]
