New UCD1+ for SIA protocol
womullan at skysrv.pha.jhu.edu
Wed Mar 24 10:56:55 PST 2004
At the risk of being told this laready and having forgotten ...
why do the standard ones like
I thought this was a move to reomve the VOX: not
rename all ucds ...
Although I like the dots more than the _..
this will break lots of apps which rely on thoose ucds ..
On Wed, Mar 24, 2004 at 10:45:35AM -0800, Roy Williams wrote:
> Dear UCD and DAL folks
> Three of us (Sebastian Derriere, Andrea Preite-Martinez, myself) have been
> working on an update for the SIA protocol that uses the standard UCD set,
> now called UCD1+, rather than the ad hoc namespace VOX that SIA 1.0 has been
> In the following, all UCD from the original SIA specification are listed
> below. The old SIA UCD is written first, then the suggested new UCD1+ is
> written in the line beginning "-->"
> The UCD1+ is not fully documented yet, but you can find a dictionary from
> UCD1 to UCD1+ at
> The SIA protocol is defined at
> The new SIA will be version 1.1, and we are hoping to draft and approve this
> at the IVOA meeting at the end of May.
> Thank you for your comments and suggestions on these new assignments
> Andrea, Roy, Sebastian
> --> meta.title
> containing a short (usually one line) description of the image. This should
> concisely describe the image to a user, typically identifying the image
> source (e.g., survey name), object name or field coordinates,
> bandpass/filter, and so forth.
> --> meta.id;instr
> identifying the instrument or instruments used to make the observation,
> --> time.epoch
> representing the mean modified Julian date of the observation.
> --> pos.eq.ra
> representing the ICRS right-ascension of the center of the image.
> --> pos.eq.dec
> representing the ICRS declination of the center of the image.
> --> pos.wcs.naxes
> specifying the number of image axes.
> --> pos.wcs.naxis
> with the array value giving the length in pixels of each image axis.
> --> instr.scale
> with the array value giving the scale in degrees per pixel of each image
> --> meta.code.mime
> specifying the MIME-type of the object associated with the image acref,
> --> pos.frame
> representing the coordinate system reference frame, selected from "ICRS",
> "FK5", "FK4", "ECL", "GAL", and "SGAL".
> --> time.equinox
> representing the Equinox (not required for ICRS) of the coordinate system
> --> pos.wcs.ctype
> the array value being the three-character code ("TAN", "ARC", "SIN", and so
> forth) specifying the celestial projection
> --> pos.wcs.crpix
> with the array value specifying the image pixel coordinates of the WCS
> reference pixel. This is identical to "CRPIX" in FITS WCS.
> --> pos.wcs.crval
> with the array value specifying the world coordinates of the WCS reference
> pixel. This is identical to "CRVAL" in FITS WCS.
> --> pos.wcs.cdmatrix
> with the array (matrix) value specifying the WCS CD matrix. This is
> identical to the "CD" term in FITS WCS, and defines the scale and rotation
> (among other things) of the image.
> --> instr.bandpass
> identifying the bandpass by name (e.g., "V", "SDSS_U", "K", "K-Band", etc.).
> --> meta.unit
> identifying the units used to represent spectral values, selected from
> "meters", "hertz", and "keV".
> --> em.wl OR em.freq OR em.energy
> specifying the characteristic (reference) frequency, wavelength, or energy
> for the bandpass model.
> --> em.wl;stat.max OR em.freq;stat.max OR em.energy;stat.max
> specifying the upper limit of the bandpass.
> --> em.wl;stat.min OR em.freq;stat.min OR em.energy;stat.min
> specifying the lower limit of the bandpass.
> --> meta.code
> specifying the type of processing done by the image service to produce an
> output image pixel.
> --> meta.ref.url
> specifying the URL to be used to access or retrieve the image.
> --> time.interval;stat.min
> specifying the minimum time to live in seconds of the access reference.
> --> phys.size;meta.file
> representing the actual or estimated size of the encoded image in bytes (not
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