HR: 1340h
AN: S33B-0325    [Abstracts]
TI: Southern California Seismic Network: New Design and Implementation of Redundant and Reliable Real-time Data Acquisition Systems
AU: * Saleh, T
EM: tsaleh@gps.caltech.edu
AF: Caltech Seismo Lab, 252-21, Pasadena, CA 91125 United States
AU: Rico, H
EM: hugo@gps.caltech.edu
AF: Caltech Seismo Lab, 252-21, Pasadena, CA 91125 United States
AU: Solanki, K
EM: solanki@gps.caltech.edu
AF: Caltech Seismo Lab, 252-21, Pasadena, CA 91125 United States
AU: Hauksson, E
EM: hauksson@gps.caltech.edu
AF: Caltech Seismo Lab, 252-21, Pasadena, CA 91125 United States
AU: Friberg, P
EM: pfriberg@isti.com
AF: Instrumental Software Tech. Inc, PO Box 963, New Paltz, NY 10964 United States
AB: The Southern California Seismic Network (SCSN) handles more than 2500 high-data rate channels from more than 380 seismic stations distributed across southern California. These data are imported real-time from dataloggers, earthworm hubs, and partner networks. The SCSN also exports data to eight different partner networks. Both the imported and exported data are critical for emergency response and scientific research. Previous data acquisition systems were complex and difficult to operate, because they grew in an ad hoc fashion to meet the increasing needs for distributing real-time waveform data. To maximize reliability and redundancy, we apply best practices methods from computer science for implementing the software and hardware configurations for import, export, and acquisition of real-time seismic data. Our approach makes use of failover software designs, methods for dividing labor diligently amongst the network nodes, and state of the art networking redundancy technologies. To facilitate maintenance and daily operations we seek to provide some separation between major functions such as data import, export, acquisition, archiving, real-time processing, and alarming. As an example, we make waveform import and export functions independent by operating them on separate servers. Similarly, two independent servers provide waveform export, allowing data recipients to implement their own redundancy. The data import is handled differently by using one primary server and a live backup server. These data import servers, run fail-over software that allows automatic role switching in case of failure from primary to shadow. Similar to the classic earthworm design, all the acquired waveform data are broadcast onto a private network, which allows multiple machines to acquire and process the data. As we separate data import and export away from acquisition, we are also working on new approaches to separate real-time processing and rapid reliable archiving of real-time data. Further, improved network security is an integral part of the new design. Redundant firewalls will provide secure data imports, exports, and acquisition as well as DMZ zones for web servers and other publicly available servers. We will present the detailed design of this new configuration that is currently being implemented by the SCSN at Caltech. The design principals are general enough to be of use to most regional seismic networks.
DE: 7200 SEISMOLOGY
SC: Seismology [S]
MN: Fall Meeting 2005