Projects at the NCEDC
Several projects are underway at the NCEDC to improve or enhance access to data. If you are planning on attending the Fall 2002 meeting of American Geophysical Union, stop by and visit our poster on Sunday morning!
- NCEDC and SCEDC collaboration
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This year, the NCEDC wrote a collaborative proposal with the SCEDC to the Southern California Earthquake Center, with the goal of unifying data access between the two data centers. As part of this project, the NCEDC and SCEDC are working to support a common set of 3 tools for accessing waveform and parametric data: SeismiQuery, NetDC, and STP.
The Seismogram Transfer Program or STP is a GUI-based client-server program, developed at at the SCEDC. Access to STP is either through a simple direct interface that is available for Sun or Linux platforms or through a Web interface. With the direct interface, the data are placed directly on a users' computer in several possible formats, with the byte-swap conversion performed automatically. With the Web interface, the selected and converted data are retrieved with a single ftp command. The STP interface also allows rapid access to parametric data such as hypocenters and phases.
The NCEDC has started implementing STP, working with the SCEDC on extensions and needed additions.
- SEED format data and the NCSN
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Providing access to data from the Northern California Seismic Network in SEED format has been an ongoing project. In the last year, the USGS compiled the necessary descriptions for for both historic and current NCSN instrumentation. The NCEDC and USGS jointly developed a procedure to create and maintain the hardware attributes and instrument responses at the NCEDC for the 3500 NCSN channels. We anticipate that NCSN data will be distributable in SEED format before the end of the calendar year! When completed, data from all major networks will be accessible using the same interfaces.
- GSAC project
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Since 1997, the NCEDC has collaborated with UNAVCO and other members of the GPS community on the development of the GPS Seamless Archive Centers (GSAC) project. When completed, this project will allow a user to access the most current version of GPS data and metadata from distributed archive locations. The NCEDC is participating at several levels in the GSAC project: as a primary provider of data collected from core BARD stations and USGS MP surveys, as a wholesale collection point for other data collected in northern California, and as a retail provider for the global distribution of all data archived within the GSAC system. We have helped to define database schema and file formats for the GSAC project, and for several years have produced complete and incremental monumentation and data holdings files describing the data sets that are produced by the BARD project or archived at the NCEDC so that other members of the GSAC community can provide up-to-date information about our holdings. Currently, the NCEDC is the primary provider for over 74,000 data files from over 1400 continuous and survey-mode monuments. The data holdings records for these data have been incorporated into a preliminary version of the retailer system currently undergoing testing, which should become publicly available in late 2002.
- Database Project
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Most of the parametric data archived at the NCEDC, such as earthquake catalogs, phase and amplitude readings, waveform inventory, and instrument responses have been stored in flat text files. Flat file are easily stored and viewed, but are not efficiently searched. Over the last year, the NCEDC, in collaboration with the SCED and TriNet, has continued development of database schemas to store the parametric data from the joint earthquake catalog, station history, complete instrument response for all data channels, and waveform inventory.
The parametric schema supports tables and associations for the joint earthquake catalog. It allows for multiple hypocenters per event, multiple magnitudes per hypocenter, and association of phases and amplitudes with multiple versions of hypocenters and magnitudes respectively. The instrument response schema represents full multi-stage instrument responses (including filter coefficients) for the broadband data loggers. The hardware tracking schema will represent the interconnection of instruments, amplifiers, filters, and data loggers over time. This schema will be used to store the joint northern California earthquake catalog and the ANSS/CNSS composite catalog.
The entire description for the BP, BK, NN, and UL networks and data archive has been entered into the hardware tracking, SEED instrument response, and waveform tables. Programs have been developed to perform queries of waveform inventory and instrument responses, and the NCEDC can now generate full SEED volumes from the BK network based on information from the database and the waveforms on the mass storage system. The second stage of development will include the NCSN waveform inventory and later the NCSN instrument response data as they are made available.
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Northern California Earthquake Data Center
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Last modified: Mon Dec 17 17:31:07 PST 2007