experiences in the use of xml in meteorology
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Experiences in the Use of XML in Meteorology. Kirby James Meteorological Office http://www.bigfoot.com/~pkjames. Meteorology - A Global Science. WMO - World Meteorological Organization. Agency of the United Nations Global Responsibilities (180+ countries) - PowerPoint PPT PresentationTRANSCRIPT
Experiences in the Use of XML in Meteorology
Kirby James
Meteorological Office
http://www.bigfoot.com/~pkjames
Meteorology - A Global Science
WMO - World Meteorological Organization
• Agency of the United Nations
• Global Responsibilities (180+ countries)
• Co-ordination of Observations, Standards, Reference and Training
• Six Official Languages - English, French, Spanish, Russian, Arabic & Chinese
Reference Material Dictionaries & Glossaries
• ideal application for XML & style sheets
• multi-language support
• single source - multiple outputs in different formats – paper (RTF)– Web (HTML)– on-line database (XML)
Oxford English Dictionary
Oxford English Dictionaryhttp://algonquin.uwaterloo.ca/OED/
<E> ; ENTRY
<HG> ; HEADWORD GROUP
<HL>slate</HL> ; HEADWORD LEMMA
<MPR>sl<i>e&mac.</i><su></su>t</MPR> ; M PRONOUNCIATION
(<IPR> ; IPA PRONOUNCIATION
<IPH>sle&shti.t</IPH>)
</IPR>,
<PS>v.</PS> ; PART OF SPEECH
<HO>3</HO> ; HOMONYM NUMBER
</HG>
<LB>north.</LB> and<LB>Sc.</LB> ; USAGE GEOGRAPHIC
WMO - International Meteorological Vocabulary
• 800 pages• 3,000 entries (keywords)• four languages (English, French,
Spanish, Russian)• cost $100
WMO - International Meteorological Vocabulary
A3310
automatic picture transmission syn. APT
Direct broadcast of low resolution pictures taken from a satellite to ground stations equipped with appropriate receiving devices (B1200).
transmission automatique d'images syn. APT
Mode de diffusion directe d'images satellitaires à basse résolution aux stations terrestres dotées de l'équipement de réception nécessaire (B1200).
International Meteorological Vocabulary -
Conversion to XML
• original document was available in machineable form (.RTF)
• document had high level of structure
• conversion to XML was relatively straightforward (custom Perl scripts)
International Meteorological Vocabulary - Output
• primary requirement for Web output, in a number of different formats (e.g. single language, two language, etc.)
• requirement to minimise size of HTML files
• used James Clark’s Jade parser
• used DSSSL style sheets
International Meteorological Vocabulary
PARSER(Jade)
FAIL
DTD XML
OK
DSSSL
HTML RTF XML/SGML
UK Meteorological Glossary• already in machineable form (Quark Express)
• already highly structured
• single language (few foreign terms)
• requirement to output to Web format
• requirement for topic groupings
• requirement for mathematical formulae
Meteorological Glossary Hypertext in 1906
Classification - Topics
• Existing Classification of Glossaries
• Thermometer– BT = broader term (meteorological instrument)– NT = narrower term (Wet-bulb thermometer)– RT = related term (Thermograph)
• tree-like structure with cross-links
Glossary - Mathematics
• standards not widely accepted by users and vendors
• poor support of maths by browsers
• often in-line GIFs used
• used TeX embedded in <M> tags
• <M>$$ A = \pi r^2 $$</M>
Glossary - Output
Issues?
• American Meteorological Society Glossary
• 4 years work by involving 35 individuals
• 18 months over schedule
• cost in excess of $360,000
Meteorological Codes
• Code (noun)– a system of words, letters, figures or symbols,
used to represent others for secrecy or brevity,– a system of prearranged signals used in
transmitting messages,– a set of rules on any subject
Surface Observations
• SYNOP Code– 03772 11583 72314 10182 20119 40032 51031
69901 70282 868/1 81825 86645 90710 91125
– 03772 03 UK; 772 Heathrow– 72314 7 octas cloud 230° 14 knot wind– 10182 18.2°C air temperature– 20119 11.9°C dew point– 40032 1003.2 hPa QFF
XML (Synop) Code<!DOCTYPE OMF SYSTEM "http://zowie.metnet.navy.mil/~spawar/JMV-
TNG/XML/OMF.dtd">
<Reports TStamp="914456730">
<SYN Title='AAXX' TStamp='908539200' LatLon='37.483, 130.900’ BId='471150' SName='ULLUNGDO ISLAND’ Elev='223'>
<SYID WS='4'>16124 47115</SYID>
<SYG Ceiling='3000' Vis='5000' Wind='50, 8' T='17.6' TD='14.1' P='984.4' P0='1010.4' Pd='2 2.0'
Prec='9, 12' WX='1022' Tmm=', 18.9' Clouds='8552/'>11650 80516 10176 20141 39844 40104 52020 60092 71022 8552/ 333 10189
31017 55000 70126 92064</SYG>
</SYN>
</Reports>
Meteorological Code Tables<BUFR-TABLE ID="001003">
<TITLE>WMO Region or Geographical Area</TITLE>
<BODY>
<BN> 0 </BN> <BNAME> Antarctica </BNAME>
<BN> 1 </BN> <BNAME> Africa </BNAME>
<BN> 2 </BN> <BNAME> Asia </BNAME>
<BN> 3 </BN> <BNAME> America </BNAME>
<BN> 4 </BN> <BNAME> N America </BNAME>
<BN> 5 </BN> <BNAME> SW Pacific </BNAME>
<BN> 6 </BN> <BNAME> Europe </BNAME>
</BODY>
</BUFR-TABLE>
Logical Data Model for Meteorological Data
• map projection: – projection type,
– projection orientation,
– size and shape of the earth or other body.
• projection type: – latitude/longitude or
– instantaneous space view or
– polar orbiter or
– polar stereo-graphic or
– other.
Unexpanded SGML<!ENTITY MAP-PROJECTION '
<node><and> &PROJECTION-TYPE; </and> </node>
<node><and> &PROJECTION-ORIENTATION; </and> </node>
<node><and>size and shape of the earth </and></node> ' >
<!ENTITY PROJECTION-TYPE '
<node><or>lat-long</or></node>
<node><or>instantaneous space view</or></node>
<node><or>polar orbiter</or></node>
<node><or>polar stereo-graphic</or></node>
<node><or>other</or></node> ' >
Expanded SGML <N><A>Co-ordinate system</A>
<N><A>map projection</A>
<N><A>projection type</A>
<N><O>lat-long</O></N>
<N><O>instantaneous space view</O></N>
<N><O>polar orbiter</O></N>
<N><O>polar stereo-graphic</O></N>
<N><O>other</O></N>
</N>
<N><A>projection orientation</A>
<N><O>normal</O></N>
<N><O>transverse</O></N> . . . . . etc.
Documentation & Interface to Legacy Database
• Custom databases used to give acceptable performance for access to multi-dimensional data-sets
• XML used to document database calls (presented in HTML)
• same XML source used to drive Web-based ad-hoc query interface
Summary• benefits greatest when ‘data’ well structured
• cost of organising poorly structured data can be exceptionally high
• until recently lack of effective tools for preparation editing of XML source
• diminishing requirement for paper output reduces benefits of multiple output formats
http://www.bigfoot.com/~pkjames