System Development

As part of ongoing efforts to improve the monitoring systems in northern California and to unify the processing systems within the CISN, the BSL and the USGS Menlo Park made progress in the development of the next generation of the northern California joint notification system of the Northern California Seismic System (NCSS). Figure 3.31 illustrates the current organization of the system. Although this approach functions reasonably well, there are potential problems associated with the separation of critical system elements by $\sim$35 miles of San Francisco Bay.

Since FY01/02 we have been working to design and implement the software for Northern California operations so that identical, complete systems operate independently at the USGS and UC Berkeley. When CISN started, independently developed systems for monitoring earthquakes operated in Southern and Northern California, Trinet and Earthworm/REDI, respectively. Each of these systems has its strengths and weaknesses, and a choice had to be made. The current design for the new Northern California system draws strongly on the development of TriNet in Southern California (Figure 3.33), with modifications to allow for local differences (such as very different forms of data acquisition and variability in network distribution). In addition, the BSL and the USGS want to minimize use of proprietary software in the system. One exception is the database program. As part of the development of the Northern California Earthquake Data Center, the USGS and BSL have worked extensively with Oracle databases, and extending this to the real-time system is not viewed as a major issue.

Figure 3.33: Schematic diagram of the planned NCSS system. The design combines elements of the Earthworm, TriNet, and REDI systems
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During the last few years, BSL staff members, particularly Pete Lombard, have become extremely familiar with portions of the TriNet software. We have continued to adapt the software for Northern California, making adjustments and modifications along the way. For example, Pete Lombard has adapted the TriNet magnitude module to northern California, where it is now running on a test system. Pete made a number of suggestions on how to improve the performance of the magnitude module and has worked closely with Caltech and the USGS/Pasadena on modifications.

The BSL and the USGS Menlo Park have implemented a system to exchange ``reduced amplitude timeseries." One of the important innovations of the TriNet software development is the concept of continuous processing (Kanamori et al., 1999). Waveform data are constantly processed to produce Wood Anderson synthetic amplitudes and peak ground motions. A program called rad produces a reduced timeseries, sampled every 5 secs, and stores it in a memory area called an ``Amplitude Data Area" or ADA. Other modules can access the ADA to retrieve amplitudes to calculate magnitude and ShakeMaps as needed. The BSL and the USGS Menlo Park have collaborated to establish the tools for ADA-based exchange. As part of the software development in northern California, a number of modules have been developed.

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