XML and Geodesy: A SOPAC Perspective

1. XML and Geodesy: A SOPAC Perspective Paul Jamason, Scripps Orbit and Permanent Array Center IGS Analysis Center Conference, Miami, June 2008

2. Director: Yehuda Bock GPS Analysts: Peng Fang Linette Prawirodirdjo Programmers: Ruey-Juin Chang Paul Jamason Ian MacLeod Melinda Squibb System Administrator: George Wadsworth XML and Geodesy: A SOPAC Perspective SOPAC Participants

3. XML and Geodesy: A SOPAC Perspective XML: An Overview • XML: eXtensible Markup Language • Framework for sharing structured data • Hierarchical tree-like structure • Extensible: users define their own elements and documents by extending base types • Encode data via element names/attributes (self-describing format) • XML schemas • Validation: reduce publication of errors • Translate XML documents (instances) to a variety of formats via stylesheets

4. XML and Geodesy: A SOPAC Perspective XML Example: siteOffsets.xml <siteOffsets xsi:schemaLocation="http://sopac.ucsd.edu/geodesy http://sopac.ucsd.edu/ns/geodesy/1.0.2/reason/procInput/offsets/siteOffsets.xsd> <offset> <fourCharacterID>ldes</fourCharacterID> <geod:sopacSiteID>ldes0000</geod:sopacSiteID> <geod:date>1999-10-16T00:00:00</geod:date> <geod:cause>co-seismic</geod:cause> <comments>Hector Mine EQ</comments> <offsetComponentMagnitude> <geod:directionalComponent>north</geod:directionalComponent> <geod:magnitude uom="mm">178.287</geod:magnitude> <geod:sigma uom="mm">2.361</geod:sigma> </offsetComponentMagnitude> -- SNIP -- </offset> </siteOffsets> http://garner.ucsd.edu/pub/gamit/setup/siteOffsets.xml

5. XML and Geodesy: A SOPAC Perspective XSD Example: siteOffsets.xsd <?xml version="1.0"?> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="http://sopac.ucsd.edu/geodesy" xmlns:geod="http://sopac.ucsd.edu/geodesy" xmlns:gen="http://sopac.ucsd.edu/general" elementFormDefault="qualified" version="1.0.2" xml:lang="en"> <xsd:include schemaLocation="includes.xsd"/> <xsd:import namespace="http://sopac.ucsd.edu/general" schemaLocation="http://sopac.ucsd.edu/ns/general/1.0.0/descriptors/spatialDescriptors.xsd"/> --SNIP-- <xsd:complexType name="offsetType"> <xsd:sequence minOccurs="1" maxOccurs="1"> <xsd:element name="fourCharacterID" type="geod:gpsSiteFourCharacterID" minOccurs="1" maxOccurs="1"/> <xsd:element name="date" type="geod:gpsDateType" minOccurs="1" maxOccurs="1"/> <xsd:element name="cause" type="geod:offsetCauseType" minOccurs="1" maxOccurs="1"/> <!-- 1 to 3 of north/east/up components here (and their mags, sigmas) --> <xsd:element name="offsetComponentMagnitude" type="geod:offsetComponentMagnitudeType" minOccurs="1" maxOccurs="3"/> </xsd:sequence> </xsd:complexType> <xsd:simpleType name="offsetCauseType"> <xsd:restriction base="xsd:string"> <xsd:enumeration value="co-seismic"/> <xsd:enumeration value="equipment change"/> <xsd:enumeration value="environmental change"/> <xsd:enumeration value="creep event"/> <xsd:enumeration value="monument disruption"/> <xsd:enumeration value="metadata correction"/> <xsd:enumeration value="processing software change"/> <xsd:enumeration value="unknown"/> </xsd:restriction> </xsd:schema>

6. Advantages Set of standards for representing data; speak a common data language Validation reduces publication of errors Field formatting Limit valid entries (e.g., receiver/antenna types) Existing software: XML schema creation XML instance validation XSLT transformation Disadvantages Size Speed (validation) Additional work Difficult to visually interpret XML Schema creation can be unpleasant Not for large data files XML and Geodesy: A SOPAC Perspective XML: (Dis)Advantages

7. XML and Geodesy: A SOPAC Perspective XML and Geodesy: Relevant Standards • Open Geospatial Community (OGC): Geographic Markup Language (GML) • http://www.opengeospatial.org/standards • Observation Collections • Filter Encoding • Dublin Core Metadata Initiative (DCMI) • Document-related • Classify dates/files/services/creators • Geodesy Standard? • Define a set of xml schemas with core spatial, temporal, nominal parameters, and extend them

8. XML and Geodesy: A SOPAC Perspective Geodesy XML Candidates • Metadata-oriented • IGS site logs • Processing setup files • Processing software front-ends (e.g., GAMIT) • Bluebooking - NGS geodetic data submission • OrbitML (GMV) - spacecraft flight parameters • RINEX, SINEX headers

9. XML and Geodesy: A SOPAC Perspective XML: Supporting Software • XML parsers/transformation software available in variety of languages • Java • Perl - Xerces • FORTRAN - xmlf90; xmlfortran • XML schema generation software • oxygenML for Eclipse • Java class generation • XMLBeans

10. XML and Geodesy: A SOPAC Perspective XML and Geodesy at SOPAC: IGS Site Logs • Overview: http://sopac.ucsd.edu/projects/xml

11. <igsSiteLog xmlns="http://sopac.ucsd.edu/ns/geodesy/doc/igsSiteLog/2004" xmlns:mi="http://sopac.ucsd.edu/ns/geodesy/doc/igsSiteLog/monumentInfo/2004" xmlns:equip="http://sopac.ucsd.edu/ns/geodesy/doc/igsSiteLog/equipment/2004" xsi:schemaLocation="http://sopac.ucsd.edu/ns/geodesy/doc/igsSiteLog/2004 http://sopac.ucsd.edu/ns/geodesy/doc/igsSiteLog/2004/igsSiteLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <siteIdentification> <mi:siteName>Scripps 5 - Mt. Soledad</mi:siteName> <mi:fourCharacterID>SIO5</mi:fourCharacterID> <mi:iersDOMESNumber>40460M006</mi:iersDOMESNumber> </siteIdentification> <siteLocation> <mi:city>La Jolla</mi:city> <mi:state>California</mi:state> <mi:country>USA</mi:country> <mi:approximatePositionITRF> <mi:xCoordinateInMeters>-2456115.13</mi:xCoordinateInMeters> <mi:yCoordinateInMeters>-4768905.79</mi:yCoordinateInMeters> <mi:zCoordinateInMeters>3439232.44</mi:zCoordinateInMeters> <mi:latitude-North>+325024.00</mi:latitude-North> <mi:longitude-East>-1171500.00</mi:longitude-East> <mi:elevation-m_ellips.>185.53</mi:elevation-m_ellips.> </mi:approximatePositionITRF> </siteLocation> <gnssReceiver> <equip:receiverType>ASHTECH Z-XII3</equip:receiverType> <equip:satelliteSystem>GPS</equip:satelliteSystem> <equip:serialNumber>LP02814</equip:serialNumber> <equip:firmwareVersion>CD00</equip:firmwareVersion> <equip:dateInstalled>2002-05-15T00:00Z</equip:dateInstalled> <equip:dateRemoved>2003-01-09T00:00Z</equip:dateRemoved> </gnssReceiver> <gnssAntenna> <equip:antennaType>ASH701945B_M</equip:antennaType> <equip:serialNumber>CR519991867</equip:serialNumber> <equip:antennaReferencePoint>BPA</equip:antennaReferencePoint> <equip:marker-arpUpEcc.>0.0083</equip:marker-arpUpEcc.> <equip:dateInstalled>2002-05-15T00:00Z</equip:dateInstalled> <equip:dateRemoved>2004-09-29T00:00Z</equip:dateRemoved> <equip:notes></equip:notes> </gnssAntenna> Sample XML IGS Site Log

12. XML and Geodesy: A SOPAC Perspective XML and Geodesy at SOPAC • Time Series Plotting • GPS analysis input • Historical equipment information • Site motion model terms - apriori coords • Phase center information • GPS coordinate data submission/querying • GML Observation Collections • GML Filter Encoding • GPS time series offsets

13. XML and Geodesy: A SOPAC Perspective XML and Geodesy: Conclusion • SOPAC: support IGS/INDIGO via XML site log implementation • Widely used in other fields • Encapsulate, control, validate metadata • Appeal to IT staffs