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Science With the Virtual Observatory |
Summer school participants will gain an understanding of how the registry is organized, and how Unified Content Descriptors (UCDs) can be effectively utilized to maximize both data organization and access. Available tools will be shown that browse the UCD tree and interpret available observations. Understanding the registry structure will allow participants to build their own registry clients in later exercises and publish their own datasets and services.
Examine a table of data and ask yourself some questions:
331061 456-013 00 00 02.3 +15 52 52 0.4 0.3 3 0.82 0.87 0.90 0.11 0.68 5.8 6001 246 252 249 271 331060 478-009b 00 00 03.4 +23 05 15 1.1 0.1 5 1.86 2.05 2.73 0.36 1.01 12.5 4461 166 180 178 187 331405 00 00 03.5 +26 00 50 0.8 0.3 3 2.27 2.47 2.78 0.32 1.29 8.3 10405 318 328 318 337 331066 382-016 00 00 12.7 +01 07 12 0.8 0.5 4 2.24 2.44 2.60 0.33 1.63 7.1 7326 347 363 346 376 331067 517-010 00 00 22.2 +34 36 58 0.6 0.5 5 0.62 0.67 0.68 0.13 1.34 4.1 12703 143 163 152 187 12893 456-014 00 00 28.4 +17 13 13 2.0 1.8 10 2.40 3.24 3.28 0.44 3.87 9.2 1099 68 89 75 98 12896 478-010 00 00 31.4 +26 19 31 1.0 0.9 3 2.58 2.90 2.94 0.36 2.36 7.1 7666 187 220 199 256 12898 00 00 37.4 +33 36 02 1.0 0.4 5 4.32 4.78 5.34 0.56 0.94 32.6 4780 193 202 187 211 12897 499-032 00 00 38.0 +28 23 03 1.2 0.3 2 0.50 0.55 0.64 0.09 0.46 5.4 8864 308 308 297 391 12895 00 00 38.3 +20 03 32 1.2 0.9 10 3.74 4.27 4.42 0.47 1.99 13.6 6747 168 180 164 198 331071 499-033 00 00 44.2 +28 24 05 0.6 0.4 2 0.32 0.34 0.36 0.05 0.29 4.9 8610 425 461 436 659 12900 456-015 00 00 55.9 +20 20 17 2.0 0.1 5 8.61 10.89 14.86 2.26 1.48 21.9 6804 436 455 431 465 36544 349 G 17 00 00 57.7 -33 36 47 1.5 1.2 5 3.58 3.77 3.87 0.43 3.40 9.7 6911 150 162 155 169 12901 499-035 00 00 58.9 +28 54 41 1.8 0.7 3 3.79 5.14 5.76 0.77 1.15 18.0 6895 399 424 397 427 12903 408-010 00 01 08.3 +06 20 14 1.1 0.2 4 3.49 3.85 4.72 0.60 1.64 6.1 14747 595 617 608 623 12909 I5376 00 01 19.8 +34 31 32 2.1 0.4 2 5.48 6.73 8.21 1.16 3.28 6.6 5028 435 445 443 450 12906 N7803 00 01 20.0 +13 06 40 1.0 0.7 0 3.91 4.34 4.53 0.46 1.25 13.0 5326 271 358 282 407
The "word" listing for Unified Content Descriptors (UCDs) was mined from 5000 astronomical data tables and their associated metadata of all difference sizes and types. UCDs are phenomenological and are inherently fuzzy, and are meant to be a descriptive semantic type.
NOTE: The IVOA UCD working group has been superceded by the Semantics Working Group. (June 20,2006)
Often in astronomy, quantities have similar names and meanings. Namespaces acts as a container for the identifiers held within, such that names are not ambiguous (similar to biological nomenclature) - ie error that is part of a magnitude namespace or error that is part of a spectal namespace. Another example is the name binary - it can belong to the namespace galaxy, star, or asteroid. Yet, another example is in MySQL - the databases you create are namespaces (containers) for tables. You may have tables of the same name in different databases.
[namespace:] w.o.r.d; [namespace:] w.o.r.d; ....
struct Myposition {
pos.eq.ra alpha;
pos.eq.dec delta;
....}
utype is a data-model-part
struct VOStandardPosition {
float RA;
...}
Read about the IVOA Standard vocabulary.
<Group name="SQUARE_GALAXY_FLUX">
<Param name="counts" value="73288" unit="ct" ucd="phot.count"/>
<Param name="peak" value="1310" unit="ct/s" ucd="arith.rate;phot.count"/>
</Group>
<Param name="seeing" value="2" unit="arcsec" ucd="instr.obsty.site.seeing"/>
The NVO Summer School is made possible through the support of the National Science Foundation and the National Aeronautics and Space Administration.
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