Accessing Seismological Services in a Web Services Environment
Tim Ahern, IRIS (IRIS Data Management System), US
Authors: Tim Ahern, Joanna Muench, and Linus Kamb (IRIS Data Management Center)
The distribution of seismic data remains a key responsibility of IRIS. Over the last 20 years, the means of providing access to data has shifted with technological changes from sending tapes via surface mail to high-speed data transfers. An increasing priority is enabling programmatic access to data and analysis tools, as well as providing capability for members of the seismic community to share a wider variety of data products. Adoption of a service-oriented architecture at IRIS is a critical means to these goals.
IRIS initiated our service-oriented approach beginning in 1998 with introduction of the CORBA-based Data Handling Interface (DHI). The DHI provides programmatic access to multiple seismic data centers through Java and C/C++ clients. More recently, the commonly used program SAC (Seismic Analysis Code) has been updated to interface with DHI, bringing data access and analysis tools together. Noting the maturation of web services into an accepted data service technology, IRIS has developed a prototype web service version of the DHI using the SOAP protocol.
In the near future, IRIS will release DHI 2.0. This new version will encompass both CORBA and SOAP technologies to provide users with data access technologies most appropriate for their needs. Also in development is the Searchable Product Archive and Distribution Engine (SPADE), a tool to allow registered data producers from locations across the globe to make their products available to the community. With SPADE, scientists will be able to discover data sources through a single SOAP interface, searching via spatial and temporal and product-specific metadata.
As we move forward, IRIS will continue to integrate and provide access to its data and analysis tools programmatically, as components of web sites and as stand-alone applications. Web service and portlet technologies allow easy incorporation of IRIS tools and data into research programs, educational websites and government planning. IRIS is moving toward exposing all of its information holdings through well documented interfaces leveraging Web Service technologies.
keywords: Web Services, Service Oriented Architecture, Seismology, Earthquakes