LMU, Geophysics Robert Barsch

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LMU, Geophysics Robert Barsch
WEB-BASED TECHNOLOGY IN SEISMOLOGY
FOR STORAGE, PROCESSING AND SIMULATION OF
MULTI-COMPONENT DATA
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Web-based technology in seismology
Table of contents

• Project details
• Web services
• XML
• SeisHub
• Database design issues
• Cooperation w/ Orfeus NERIES

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Web-based technology in seismology
Project details

• Design of a new open source, modular,
  multi-component database structure accessible via
  web services
• Extension of standard processing tools (SH/SHM,
  Qt-Pitsa)
• Link between database, multi-component
  processing tools and executable simulation
  algorithms (SPICE)
• Development of formats and standards to combine
  the joint storage and processing of observations
  and simulations
• 3-year DFG grant until Oct 2009

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Web-based technology in seismology
Web services

• Wikipedia a software system designed to support
  interoperable Machine to Machine interaction over
  a network. Web services are frequently just Web
  APIs that can be accessed over a network, such as
  the Internet, and executed on a remote system
  hosting the requested services.
• Styles
• REST
• SOAP (message based)
• RPC (distributed function call)
• Examples
• Web 2.0 Google Map, Map24, Flickr
• Amazon Web Services, Google Web APIs
• Search engines Google, Yahoo

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Web-based technology in seismology
Web services

• Advantages
• Platform independent - relying on standards
  XML, HTTP, SOAP, UDDI, WSDL
• No firewall problems (HTTP)
• Security authorization (HTTP Auth), data
  encryption (XML encryption, XML signature),
  secure data transfer (HTTPS)
• License free
• Disadvantages
• Slower than common solutions
• XML parsing
• data overhead (XML verbosity, SOAP envelop)
• Infrastructure (application server etc.)
• Seismologists ! IT nerds

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Web-based technology in seismology
Extensible Markup Language (XML)

• Simple, vendor-neutral textual representation
  for structured data
• Human and machine-readable format (verbose)
• Unicode support
• Represents the most general computer science
  data structures records, lists and trees
• Platform-independent
• W3C standard
• Correctness
• Well-formedness by design (all elements are
  properly nested within each other, without
  overlapping)
• Validity, if document complies with a particular
  XML schema
• gt ideal for data interchange

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Web-based technology in seismology
Extensible Markup Language (XML)
Example (ASCII) Last SED alarm Date UTC
2004/03/17 160310.3 Region Kloental /
Switzerland Latitude 47.1 N deg Longitude 9.1 E
deg Magnitude ML 1.5 Depth 0 km
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Web-based technology in seismology
Extensible Markup Language (XML)
Example (XML) lt?xml version"1.0"
encoding"UTF-8"?gt ltlocation main"true"
xmlns"http//quakeml.ethz.ch/ns/eventlist/locatio
n"gt ltorigin-time timezone"0000"gt
ltyeargt2004lt/yeargtltmonthgt03lt/monthgtltdaygt17lt/daygt
lthourgt16lt/hourgtltminutegt03lt/minutegtltsecondgt10.3lt/
secondgt lt/origin-timegt ltlatitude
unit"degree"gt47.1lt/latitudegt ltlongitude
unit"degree"gt9.1lt/longitudegt ltdepth
unit"km"gt0lt/depthgt ltmagnitude
unit"ML"gt1.5lt/magnitudegt ltregiongtKloental /
Switzerlandlt/regiongt lt/locationgt
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Web-based technology in seismology
Extensible Markup Language (XML)

• XSLT transforming and formating of XML documents
• XML XSLT gt XML
• Output formats
• XML
• XHTML
• SVG
• PDF (XSLFO)
• PS (XSLFO)
• XSLT
• RSS
• XML Mapping Tools

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Web-based technology in seismology
SeisHub

• SeisHub
• Web Server w/ plugin architecture
• HTML based Administration Interface
• RESTful data access
• fixed ressource identifier (URIs)
• XSLT processing (XML, XHTML) based on request
• Software
• Python 2.4
• Twisted
• Database Python DB API SQLAlchemy (ORM)
• Status
• dropped Native XML DB support (Oracle Berkeley
  DB XML)
• focus on reliable relational database design

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Web-based technology in seismology
Database design issues
Relational DB vs. Native XML DB

• Solution archive XML documents into SQL
  database
• XML -gt Blob (zipped)
• index fields

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Web-based technology in seismology
Cooperation w/ Orfeus NERIES

• XML standard(s) gt QuakeML?
• Unique IDs for Quakes
• Global repository of common resources
  (datalogger, seismometers, persons, working
  groups, )
• - distributed Semantic Web (RDF)
• - centralized Web Service

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Web-based technology in seismology
Coming soon www.seishub.org
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