Transcript GIS Data and Services

GML Data Models and Web
Services for GPS and
Earthquake Catalogs
Marlon Pierce, Galip Aydin
Community Grids Lab,
Indiana University
[email protected]
QuakeSim Applications
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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
catalogs.
• RDAHMM primarily used with GPS data
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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
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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
Web Services framework is
a way for doing distributed
computing with XML.

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XML provides crosslanguage support
Suitable for both human
and application clients
Appl
Web
Server
WSDL
SOAP
WSDL
SOAP
Web
Server
WSDL
• WSDL: Defines interfaces
to functions of remote
components.
• SOAP: Defines the
message format that you
exchange between
components.
Browser
WSDL
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JDBC
DB
Geographical Information Service
(GIS) Data Formats and Services
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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, …
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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.
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Next Step: Implement OGC compatible Web Services for
this problem.
• Also build services to interact with QuakeTables Fault DB.
GML and Existing Data Formats
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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
•
JPL, SOPAC, USGS
GPS data formats
We defined 2 GML Schemas to unify
these
• http://grids.ucs.indiana.edu/~gaydin/servo
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A summary of all supported formats and
data sources can also be found there.
So We Built It
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First version of the
system available
• Tried XML databases
but performance was
awful
• Currently database uses
MySQL
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Download results are
in GML, but we can
convert to appropriate
text formats.
Search DB For Earthquake
Catalogs
Results
Search XML DB For GPS Catalogs
1
Use Ours or Set Up Your Own
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URL to access our browser interface:
• http://gf3.ucs.indiana.edu:6060/cce/sql/
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URL to download and set up your
own
• http://complexity.ucs.indiana.edu/~gaydin/cce
/install/install.html
Fault Quest: QuakeTables+OGC
Web Map Service Demo
http://rio.ucs.indiana.edu:8080/wmsClient/
Conclusions
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This is a little discussion with a big
conclusion-If you want to build iSERVO or
something like it, data access
services are an important
foundation.
GML Schemas as Data Models for
Services
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Fault and GPS Schemas are based on GMLFeature object.
Seismicity Schema is based on GML-Observation
object.
Working schema available from
http://grids.ucs.indiana.edu/~gaydin/schemas/
Browser Interface
JSP + Client Stubs
DB Service 1
Job Sub/Mon
And File
Services
Viz Service
JDBC
DB
Host 1
Operating and
Queuing
Systems
Host 2
RIVA
Host 3
QuakeSim Portal Shots
Other Issues
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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.
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We’d like to simplify this approach
Metadata is also important
• Useful for capturing data pedigree and validation.
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“This fault data generated with Simplex by Jay Parker using the
parameters….”
“Those 1935 Fault measurements aren’t so good.”
We have developed some general applications for metadata
management
• Newsgroups, citations, references, glossaries as examples.
• Would like to apply to scientific metadata
Future Directions
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We are interested in Semantic Web markups (particularly
RDFS) to provide metadata descriptions of
•
•
•
•
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Instruments
Data sets
Computing hardware
Applications/codes
We want this to form the basis for building composite
services.
Infrastructure improvements: reliable, fault tolerant grid
infrastructure needed as grid components come and go.
Component based portals: reuse portal interfaces between
projects.
ISERVO: International collaborations with Australia, Japan,
and possibly other countries
• Through ACES: APEC Cooperation for Earthquake Simulation
Acknowledgements
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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
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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.
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Data files often created by hand from
journals, online repositories
• Online repositories themselves use differing
formats
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Challenges are to develop common data
formats, access services, and client
query tools.
Web Services for Data Access and
Computing Service Invocation
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Web services:
• WSDL: Interface definition language, describes your
service
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“GeoFEST may be invoked with these input types”
• SOAP: Transport envelope for remote procedure
calls/messages
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“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
values
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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,…
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Work underway to build data services
QuakeSim Basics
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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
audience
• 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
project.
• SCIGN is adopting a Web Services approach for GPS data.
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Formats defined but presented as text
• Use XML to re-format the data.
• Buys us investment in many XML manipulation, validation, and
messaging tools.
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We wanted to use databases to store and manage the
information.
This makes the data queryable
• Retrieve all entries > 1970
• Retrieve all entries with M>3.0
Data Sources Summary
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A summary of all supported
formats can be found here
• http://grids.ucs.indiana.edu/~gaydin/
servo
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Information about supported
Earthquake catalog formats can be
found in
http://www.data.scec.org/
Information about supported GPS
data formats can be found in
http://www.scign.org
What Are Web Services?
Web services framework is
a way for doing distributed
computing with XML.


XML provides crosslanguage support
Suitable for both human
and application clients
Appl
Web
Server
WSDL
SOAP
WSDL
SOAP
Web
Server
WSDL
• WSDL: Defines interfaces
to functions of remote
components.
• SOAP: Defines the
message format that you
exchange between
components.
Browser
WSDL

JDBC
DB
Delivering Data for Human and
Application Consumption
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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