New list of words
Alberto.Micol at eso.org
Tue May 3 01:54:53 PDT 2005
> I'm sure you'll have other before Kyoto!
I'm taking it seriously :-) Here some other comments, in no particular
1. pos.frame exists, can we also add the spect.frame and time.frame?
2. instr.spec: probably not needed
because otherwise we would also need instr.imager, and similarly for
other kinds of instruments.
instr.spect.dispersion could simply be instr.dispersion
instr.spect.order " " " instr.order
(in fact there is no need to say instr.imager.scale, instr.scale is
3. Transmission (an old friend of mine): some time ago Sebastien and I
exchanged some emails
and, if I remember correctly, we agreed that there should be a
which could be attached to any of: instr.det, instr.filter, instr to
between the transmission/sensitivity of the various components
(detector, filter, optical elements)
and the overall transmission (filter * detector * optical elements)
including even the atmosphere
4. instr.sensitivity; Its description reads: Instrument sensitivity,
I would say that sensitivity and detection threshold, while linked,
are two different concepts,
and would be better to split that one into 2 different UCDs
5. Descriptions: sometimes the description of a ucd is ambiguous, e.g.:
a. instr.tel.focus (Q): Telescope focus
b. instr.bandpass (Q): Bandpass of instrument
c. instr.pixel (S): Pixel
a. Is instr.tel.focus the "name" of the telescope focus (eg
or the focal length of the telescope?
How many services will make use of this ucd to describe a table
column that contains
the numeric transmission at a given wavelength of a given filter?
Some other service will use this ucd to describe the name of the
bandpass (or the filter name).
Which one of the two is legitimate, both? (see (3) above).
c. Another, though different, example is the instr.pixel
I can think of a catalog associated with an image, where X and Y
at which detector coordinates the source was found
But it can be used to indicate the pixel scale of the detector
The fact is that instr.pixel is a Secondary word, hence its
meaning could be broader.
For that reason probably both above mentioned cases are
legitimate: instr.pixel is only an
attribute (an adjective in a grammar-speak).
I think it is very important to be clear, especially on those words
that could be Primary,
because otherwise people might misuse UCDs and that would make the
entire concept collapse.
6. Abbreviations: Why temperature is some times abbreviated and some
other times not?
(e.g., instr.skyTemp, phot.antennaTemp, phys.temperature) Wouldn't
be better to be
7. wcs information
pos.wcs.ctype: How would the software recognise ctype1 from ctype2 ?
Would it be possible to say:
pos.wcs.ctype;arith.first and pos.wcs.ctype;arith.second?
Or maybe (see cdmatrix below): arith.1 and arith.2
The same for pos.wcs.crpix, crval and naxis
pos.wcs.cdmatrix: how to distinguish the various matrix elements?
what about accompaining the cdmatrix with a
arith.1_1, arith.1_2, etc.?
That arith.1, etc. could be useful to rank things.
8. question regarding files
meta.file exists; how can I describe the size (eg in bytes) of a
file? and its CRC?
Probably enough for this morning... ;-)
And, beware, I might come back with more DM issues. :-)
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