Data Services Newsletter

Volume 2 : No 1 : March 2000

Portable Data Collection Center

In the past, a local Data Collection Center (DCC) was forced to develop their own set of tools if they wanted to build SEED volumes from the data at their institution. Because the SEED format is complex (to say the least), generation of valid SEED volumes required a lot of time and effort on the part of each DCC. In addition, because each DCC tended to write tools that were specific to the way that they stored their data internally and because very few local DCCs store their data in the same manner, there was no way for one DCC’s “seed writer” to be adopted by another DCC. In order to avoid this problem, a more standard approach to the process of building SEED volumes was needed. The Portable Data Collection Center (PDCC) Toolkit is a graphical user interface (GUI) designed to aid in this process.

The PDCC Toolkit uses a relational database to store the metadata associated with the data channels that make up a DCC’s network. The relational database keeps this information in a form that can be easily maintained by the network operator. In addition, one can use the tools included in the Toolkit to build either a full SEED volume or a dataless SEED volume for all or any part of a network. The Toolkit uses a MySQL relational database management system (RDBMS). This database was chosen primarily because it met all of the requirements for the project: it is free (or at least it’s free for noncommercial use), it has an SQL interface that supports the vast majority of the SQL92 “standard”, and there is a Type4 JDBC driver freely available for this database. In addition, this RDBMS is available for a wide variety of platforms (Solaris, Linux, and even Windows), and it is actively supported by a commercial development effort. Finally, this RDBMS provides a great deal of flexibility in terms of granting users access to the database.

The current release of the Networked Data Centers (NetDC) package also includes a pre-built interface to the PDCC Toolkit. This interface allows users to make requests for station inventories, channel inventories, channel responses, waveform inventories, and waveforms directly from any DCC that is using the PDCC Toolkit to maintain their network’s data and metadata (with no extra effort required by the DCC other than installation and configuration of these two packages). We hope that this additional feature makes the PDCC Toolkit an even more attractive solution for any DCC that is interested in filling user requests for data locally at their own DCC.

There are plans to add several features in future releases of the Toolkit including support for generation of data synchronization files, waveform quality control tools to help the user detect and document problems with their data, and integration with external Java-based analysis and display packages as they become available. These features are not included in the current release.

If you are interested in learning more about setting up a PDCC at your facility, you can download a copy of the PDCC Toolkit Technical Manual in Adobe Acrobat format (.pdf) or contact Tom McSweeney at the DMC.

by Tom McSweeney (IRIS Data Management Center)

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