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Web Gridded Document Service (WGDS) The Air Transportation Information Exchange Conference (Featuring AIXM, WXXM, and FIXM). Paul Hershberg Meteorological Development Laboratory Office of Science and Technology NOAA’s National Weather Service August 28-30, 2012.
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Web Gridded Document Service (WGDS)The Air Transportation Information Exchange Conference (Featuring AIXM, WXXM, and FIXM) Paul Hershberg Meteorological Development Laboratory Office of Science and Technology NOAA’s National Weather Service August 28-30, 2012
Materials from this presentation will be available athttp://www.mdl.nws.noaa.gov/~WGDSuntil September 30, 2012.
National Digital Forecast Database National Centers Model Guidance • Created in 2004 • Sensible Wx • Detailed • Interactive • Collaborative Grids Local Digital Forecast Database Field Offices National Centers Collaborate Data and Science Focus NWS Automated Products User-Generated Products National Digital Forecast Database TODAY...RAIN LIKELY. SNOW LIKELY ABOVE 2500 FEET. SNOW ACCUMULATION BY LATE AFTERNOON 1 TO 2 INCHES ABOVE 2500 FEET. COLDER WITH HIGHS 35 TO 40. SOUTHEAST WIND 5 TO 10 MPH SHIFTING TO THE SOUTHWESTEARLY THIS AFTERNOON. CHANCE OF PRECIPITATION 70%. Digital Text Graphic Voice
Legacy NDFD Web Feature Services Data Flow –> Grids to Documents Field Offices NDFD Central Server System (GRIB2 Grids) NWS WEB SERVICE (SOAP/REST) Public Businesses Government Data Request Data Response: NDFD XML Document encoded in DWML National Centers -- User selects between two types of products, time constraints, unit, and up to 57 forecast weather elements. ** ~ 12 Million Hits a Day **
DWML Example Current Service: Summary (12 hr) <data> !! Note the lack of OGC prefixes <location> <location-key>point1</location-key> <point latitude="48.22" longitude="-106.62"/> </location> <moreWeatherInformationapplicable- location="point1">http://forecast.weather.gov/MapClick.php?textField1=48.22&textField2=-106.62 </moreWeatherInformation> <time-layout time-coordinate="local" summarization="12hourly"> <layout-key>k-p24h-n7-1</layout-key> <start-valid-time period-name="Today">2008-12-05T06:00:00-07:00</start-valid-time> <end-valid-time>2008-12-05T18:00:00-07:00</end-valid-time> </time-layout> <weather time-layout="k-p12h-n14-3"> <name>Weather Type, Coverage, and Intensity</name> <weather-conditions weather-summary="Slight Chance Snow"> <value coverage="slight chance" intensity="light" weather-type="snow" qualifier="none"/> </weather-conditions> </weather> </data>
DWML Example Current Service: Meteogram <temperature type="maximum" units="Fahrenheit" time-layout="k-p24h-n7-1"> <name>Daily Maximum Temperature</name> <value>36</value> <value>29</value> <value>33</value> <value>20</value> <value>37</value> <value>18</value> <value>14</value> </temperature> <severe-component type="tornadoes" units="percent" time-layout="k-p24h-n1-11"> <name>Probability of Tornadoes</name> <value>0</value> </severe-component> <climate-anomaly> <seasonal type="average temperature above normal" units="percent" time-layout="k-p3m-n3-2"> <name>Probability of Three-Month Average Temperature Above Normal</name> <value>42</value> <value>44</value> <value>38</value> </seasonal> </climate-anomaly>
Legacy NDFD Web Service Limitations Field Offices • NotOGC compliant • Service paradigm does not fit established service models (WCS, WFS, WMS) NDFD Central Server System (GRIB2 Grids) NDFD WEB SERVICE (SOAP/REST) Public Businesses Government Data Request Data NDFD XML Document National Centers
A New Service Paradigm:Web Gridded Document Service • Exploring a new type of web service • Will be patterned after a Web Coverage Service (WCS) • Will respond to WCS operations similar to getCapabilities, describeCoverage, and getCoverage • Will continue to use a nearest neighbor technique for querying points from grids • Responses to a getWGDSCoverage operation will be XML documents encoded in WXXM or DWML, marking the first time NOAA gridded data will be encoded in WXXM
Top Level WGDS Depiction WSDL SOAP getCapabilities Backing Store of Gridded Data WCS Backing Store of Gridded Data WCS SOAP SOAP SOAP SOAP describeCoverage describeCoverage describeCoverage NetCDF NetCDF SOAP SOAP SOAP getCoverage getCoverage • Inputs • Wx Element(s) • Time Constraints • Doc Format (WXXM/DWML) • Inputs • Product • Lat/Lon Point(s) • Input • Service Name (WGDS) SOAP SOAP NetCDF NetCDF SOAP getWGDSCapabilities WGDS WGDS WGDS SOAP • Outputs • Version • Products (4) • Outputs • Wx Element(s) • Time Constraints • Choice Doc Format (WXXM/DWML) describeWGDSCoverage • Output • Link to XML Doc (WXXM/DWML) describeWGDSCoverage SOAP getWGDSCoverage WXXM Doc
Rationale For The New Web Service • Popularity of current service demonstrates the need for XML documents queried from grids. Recent 10-fold increase in hit count underscores this usage • The request-response paradigm deviates significantly from existing SOAP functionality due to the type of datasets • Customers value NWS post-processed data (summarized/interpreted) of current service
NEW WGDS Doc in WXXM: Summary (12 hr) Example <wx:FeatureCollectiongml:id=“id0“> NOTE OGC prefixes <wx:featureMember> <wx:Forecastgml:id=“id1”> <om:samplingTime/> <om:procedurexlink:href="urn:fdc:mdl-nextgen.nws.noaa.gov:Dataset:NDFD"/> <om:observedPropertyxlink:href="wxont:weather"/> <om:featureOfInterest/> <om:result> <wx:WxFeatureCollectiongml:id="id5"> <wx:WxfeatureMember> <wx:PointTimeSeriesCoveragegml:id="id6"> <wx:domainSet> <wx:PointTimeSeriesDomaingml:id="id41"> <wx:TimePeriodgml:id="id42"> <gml:beginPosition>2007-11-06T22:00:00Z</gml:beginPosition> <gml:endPosition>2007-11-07T10:00:00Z</gml:endPosition> <gml:duration>PT12H</gml:duration> </wx:TimePeriod> <wx:location>45.20 -77.02</wx:location> </wx:PointTimeSeriesDomain> </wx:domainSet>
NEW WGDS Doc in WXXM: 12-hr Summary Example (cont’d) <wx:rangeSetNDFD> <nawx:Weather_NDFD <nawx:weather-conditionsweather-summary="Thunderstorms Likely"> <nawx:valuecoverage="likely" intensity="none" weather-type="thunderstorms" qualifier="none"/> <nawx:valuecoverage="likely" intensity="light"additive="and" weather-type="rain showers"qualifier="none"/> </nawx:weather-conditions> </wx:rangeSetNDFD> ---------------------------------------------------------------------------------------------------------------- <wx:rangeSetNDFD> <nawx:Hazards_NDFD> <nawx:hazard-conditions> <nawx:hazardhazardCode="HT.Y" phenomena="Heat" significance="Advisory" hazardType="long duration"> <nawx:hazardTextURL> http://forecast.weather.gov/wwamap/wwatxtget.php?cwa=usa&wwa=Heat%20Advisory</nawx:hazardTextURL> </nawx:hazard> </nawx:hazard-conditions> </nawx:Hazards_NDFD> </wx:rangeSetNDFD>
NEW WGDS Doc in WXXM: MAXT Meteogram Example <om:result> <wx:WxFeatureCollectiongml:id="id5"> <wx:WxfeatureMember> <wx:PointTimeSeriesCoveragegml:id="id6"> <wx:domainSet> <wx:PointTimeSeriesDomaingml:id="id7"> <wx:TimePeriodgml:id="id8"> <gml:beginPosition>2007-11-07T10:00:00Z</gml:beginPosition> <gml:endPosition>2007-11-07T22:00:00Z</gml:endPosition> <gml:duration>PT12H</gml:duration> </wx:TimePeriod> <wx:location>45.20, -77.02</wx:location> </wx:PointTimeSeriesDomain> </wx:domainSet> <wx:rangeSetNDFD> <nawx:Temperature_NDFDtype="maximum" units="degF"> <nawx:value>83</nawx:value> </nawx:Temperature_NDFD> </wx:rangeSetNDFD> </wx:PointTimeSeriesCoverage> </wx:WxfeatureMember> </wx:WxFeatureCollection> </om:result>
POP12Hr WXXM Schema Example (snippet) <!-- NDFD PROBABILITY OF PRECIPITATION DECLARATIONS --> <element name="ProbabilityOfPrecipitation_NDFD" type="nawx:ProbabilityOfPrecipitation_NDFDType"/> <complexType name="ProbabilityOfPrecipitation_NDFDType"> <choice> <element name="value" type="nawx:percentageValType" minOccurs="0" maxOccurs="unbounded" nillable="true"/> <element name="valueList" type="nawx:valueListType" minOccurs="0" maxOccurs="unbounded" nillable="true"/> </choice> <attribute name="name" type="xsd:string" use="optional"/> <attribute name="period" type="xsd:duration" use="optional"/> <attribute name="type" use="required"> <simpleType> <restriction base="xsd:string"> <enumeration value="12 hour"/> <enumeration value="floating"/> <enumeration value="ekdmos-6 hour"/> </restriction> </simpleType> </attribute> <attribute name="units" type="xsd:string" fixed="percent"/> <attribute name="likelihoodUnits" type="nawx:likelihoodUnitsTypes" use="optional"/> <attribute name="categorical-table" type="xsd:string" use="optional"/> <attribute name="conversion-table" type="xsd:string" use="optional"/> <attribute name="applicable-categories" type="xsd:string" use="optional"/> <attribute name="probability-type" type="nawx:probability-typeType" use="optional"/> </complexType>
Summary • New Web Service (Web Gridded Document Service; WGDS) proposed • NOAA’s first attempt at creating WXXM documents from gridded data • Intend to prototype it within OWS-9 for feedback • Someday, possible adoption by OGC http://www.mdl.nws.noaa.gov/~WGDS