The Data Handling Interface (DHI) is a CORBA data access framework allowing users to access seismic data and metadata from IRIS DMC and other participating institutions directly from a DHI-supporting client program. The effect is to eliminate the extra steps of running separate query interfaces and downloading of data before visualization and processing can occur. The information is loaded directly into the application for immediate use. DHI consists of three basic service components:
1. NetworkDC - provides access to station metadata: names, locations, channels,
and instrument responses
2. EventDC - provides access to event hypocenter catalogs
3. SeismogramDC - search for available data and access waveforms
These service components run at a DHI-supported data center in the form of uniquely named 'servers' and can be discovered by a DHI 'client' application on the user's machine. This is performed by querying a data center's Naming Service, which provides a listing of available servers. Sometimes, a service component has more than one named server, each providing a specific kind of data response.
