GML Data Models and Web Services for GPS and by vev19514


									GML Data Models and Web
  Services for GPS and
  Earthquake Catalogs
    Marlon Pierce, Galip Aydin
      Community Grids Lab,
        Indiana University
               QuakeSim Applications
   Several QuakeSim codes work directly with
    observational data.
   Examples discussed at ACES include
    • GeoFEST, VirtualCalifornia, Simplex, and Disloc all depend
      upon fault models.
    • RDAHMM and Pattern Informatics codes use seismic
    • RDAHMM primarily used with GPS data
   Problem: We need to provide a way to integrate
    these codes with the online data repositories.
    • QuakeTables Fault Database was developed
    • What about GPS and Earthquake Catalogs?
    • Many formats, data available in tars or files, not searchable,
      not easy to integrate with applicaitons
   Solution: use databases to store catalog data; use
    XML (GML) as exchange data format; use Web
    Services for data exchanges, invoking queries, and
    filtering data.
        What Are Web Services?
   Web Services are not web
    pages, CGI, or Servlets       Browser
   Web Services framework is
    a way for doing distributed                                Appl
    computing with XML.
    • WSDL: Defines interfaces
      to functions of remote       Web                        WSDL
      components.                 Server
    • SOAP: Defines the                                            SOAP
      message format that you
      exchange between

      components.                                   Web
    XML provides cross-                            Server
                                 SOAP
    language support
   Suitable for both human                              JDBC
    and application clients

    Geographical Information Service
    (GIS) Data Formats and Services
   OpenGIS Consortium is an international group for defining
    GIS data formats and services.
   Main data format language is the XML-based GML.
    • Subdivided into schemas for drawing maps, representing
      features, observations, …
   First Step: design GML schemas and build specialized Web
    Services for GPS and Earthquake data.
   OGC also defines services.
    • Services include Web Features Services, Web Map Services,
      and similar.
    • These are currently pre-Web Service, based on HTTP Post, but
      they are being revised to comply with WS standards.
   Next Step: Implement OGC compatible Web Services for
    this problem.
    • Also build services to interact with QuakeTables Fault DB.
GML and Existing Data Formats
   GPS or seismic data used in this project
    are retrieved from different URLs and
    have different text formats.
   Seismic data formats
    •   SCSN, SCEDC, Dinger-Shearer, Haukkson
   GPS data formats
    •   JPL, SOPAC, USGS
   We defined 2 GML Schemas to unify
   A summary of all supported formats and
    data sources can also be found there.
                 So We Built It
   First version of the
    system available
    • Tried XML databases
      but performance was
    • Currently database uses
   Download results are
    in GML, but we can
    convert to appropriate
    text formats.
Search DB For Earthquake

Search XML DB For GPS Catalogs

    Use Ours or Set Up Your Own
   URL to access our browser interface:
   URL to download and set up your
Fault Quest: QuakeTables+OGC
    Web Map Service Demo
   This is a little discussion with a big
   If you want to build iSERVO or
    something like it, data access
    services are an important
    GML Schemas as Data Models for
   Fault and GPS Schemas are based on GML-
    Feature object.
   Seismicity Schema is based on GML-Observation
   Working schema available from
               Browser Interface

               JSP + Client Stubs

                Job Sub/Mon
DB Service 1      And File          Viz Service


                Operating and
    DB            Queuing              RIVA

   Host 1           Host 2             Host 3
QuakeSim Portal Shots
                        Other Issues
   We want to abstract the data storage system to allow
    simple federation of relational and XML databases
    • UK e-Science’s OGSA-DAI project is an interesting but
      complicated example.
           We’d like to simplify this approach
   Metadata is also important
    • Useful for capturing data pedigree and validation.
           “This fault data generated with Simplex by Jay Parker using the
           “Those 1935 Fault measurements aren’t so good.”
   We have developed some general applications for metadata
    • Newsgroups, citations, references, glossaries as examples.
    • Would like to apply to scientific metadata
                Future Directions
   We are interested in Semantic Web markups (particularly
    RDFS) to provide metadata descriptions of
    •   Instruments
    •   Data sets
    •   Computing hardware
    •   Applications/codes
   We want this to form the basis for building composite
   Infrastructure improvements: reliable, fault tolerant grid
    infrastructure needed as grid components come and go.
   Component based portals: reuse portal interfaces between
   ISERVO: International collaborations with Australia, Japan,
    and possibly other countries
    • Through ACES: APEC Cooperation for Earthquake Simulation
   Community Grids: Geoffrey Fox,
    Choonhan Youn, Galip Aydin,
    Mehmet Aktas
   NASA JPL: Andrea Donnellan (PI),
    Jay Parker, Peggy Li, Robert Granat
   UC-Davis: John Rundle
   UC-Irvine: Lisa Grant
   USC: Dennis Mcleod
   Brown: Terry Tullis
     Problems: Data Access and
      Sharing, Code Integration
   Codes all use custom text formats for
    describing input and output.
   Input and output data often combined
    with code-specific information.
    • Number of iterations, array sizes, etc.
   Data files often created by hand from
    journals, online repositories
    • Online repositories themselves use differing
   Challenges are to develop common data
    formats, access services, and client
    query tools.
Web Services for Data Access and
 Computing Service Invocation
   Web services:
    • WSDL: Interface definition language, describes your
          “GeoFEST may be invoked with these input types”
    • SOAP: Transport envelope for remote procedure
          “Invoke GeoFEST with this set of input”
   Together, WSDL and SOAP are useful for
    manipulating, returning XML data values
    • So GML schemas act as our data models and return
   Status: built several general purpose services
    • Remotely executing codes, monitoring queuing systems,
      manipulating/moving files around, describing
      applications, storing portal session values, accessing
      data bases of faults,…
   Work underway to build data services
            QuakeSim Basics
   Under development in collaboration with
    researchers at JPL, UC-Davis, USC, and
    Brown University.
   Geoscientists develop simulation codes,
    analysis and visualization tools.
   We need a way to bind distributed codes,
    tools, and data sets.
   We need a way to deliver it to a larger
    • Instead of downloading and installing the code,
      use it as a remote service.
            What’s the Problem?
   Data sources typically were provided in single downloads
    • Tar bundles or text
    • This has changed for SCEC catalogs since we developed this
    • SCIGN is adopting a Web Services approach for GPS data.
   Formats defined but presented as text
    • Use XML to re-format the data.
    • Buys us investment in many XML manipulation, validation, and
      messaging tools.
   We wanted to use databases to store and manage the
   This makes the data queryable
    • Retrieve all entries > 1970
    • Retrieve all entries with M>3.0
      Data Sources Summary
   A summary of all supported
    formats can be found here
   Information about supported
    Earthquake catalog formats can be
    found in
   Information about supported GPS
    data formats can be found in
        What Are Web Services?
   Web services framework is
    a way for doing distributed   Browser
    computing with XML.
    • WSDL: Defines interfaces                                 Appl
      to functions of remote
      components.                  Web                        WSDL
    • SOAP: Defines the           Server
      message format that you                                      SOAP
      exchange between            WSDL

   XML provides cross-
    language support              SOAP
   Suitable for both human
    and application clients                              JDBC

     Delivering Data for Human and
       Application Consumption
   We still have to get the results to the
    (remote) client.
   The client may be a user or an application.
   Web Services provide a way to do this.
   Note Web Services are NOT
    • Web pages
    • Servlets
    • CGI scripts

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