## USGS - Menlo Park, CA

Date: January 8, 1998

### Location, Contact, and Address:

Northern California Seismic Network, recorded at USGS, Menlo Park, CA

David Oppenheimer (oppen@usgs.gov) 650-329-4792
Lynn Dietz (dietz@usgs.gov) 650-329-5520
Will Kohler (kohler@usgs.gov) 650-329-4761

345 Middlefield Rd, MS 977, Menlo Park, CA 94025

### Network Characteristics:

Over 500 Analog stations, mostly short-period, vertical component, covering northern California with a few in southern Oregon

Analog data are digitized by National Instruments A/D's on two 486/DOS computers

15- continuous 16-bit DST (Digital Seismic Telemetry) stations (3 channels each)

## Standard Earthworm Modules Currently in Use

### Waveform Data Acquisition & Conversion:

- adsend - digitize waveforms, broadcast multiplexed data onto LAN. Production version runs on two 486/DOS computers, each digitizing 256 channels. A new Windows NT version of adsend which produces demultiplexed trace_buf messages has been running in parallel on a Pentium for 3 months.
- getdst2 - acquire continuous 16-bit digitally-telemetered seismic data from DST stations. Production version runs only on Pentium OS/2 computers.
- ad_demux - demultiplex waveform messages from the DOS-version of adsend into single-channel trace_buf messages.

### Rapid Earthquake Location & Notification:

For our rapid notificaton system, we run this basic Earthworm system (v2.9+) in parallel on two computers, a Pentium running Windows NT-4.0 and a Pentium running Solaris-2.6:

- coaxtoring -move broadcast waveform data from LAN onto A/D ring
- picker -pick P-arrivals from multiplexed data, output to pick ring
- binder -Carl's associator
- eqprelim, eqbuf, eqcoda, eqverify -filter, quality check, and output rapid (25-pick) pick associations
- eqproc, eqbuf, eqcoda, eqverify -filter, quality check, and output final pick associations
- hypo_mgr, hypoinv -manage and produce standard USGS hypocenter locations
- menlo_report -transfer event locations to earlybird systems for notification, archiving
- startstop, copystatus, diskmgr, statmgr (control and monitor)
- pagerfeeder -communicate with Paging PC's via serial port

### Auxiliary Tasks & Data Exchange:

In addition to our Earthworm rapid-notification computers, we have several other PC's (OS/2, NT and Solaris) which listen to the broadcast waveform data and perform other tasks.

- lptrig, trg_assoc - identify long-period events (John Evans' algorithm). Used to monitor Long Valley and Lassen regions.
- import_generic - receive Earthworm messages over a socket and write them the configured ring. Partner module to export_generic or export_scn. So far used in test-mode to import pick data from UC Berkeley and USGS-Pasadena.
- export_generic - send all Earthworm messages of a given logo to an import module over a socket. Currently used to ship hypocenters to Alaska Tsunami Warning Center (ATWC) & Alan Jones' "Seismic" and picks to UC Berkeley & USGS-Pasadena.
- export_scn -same as export_generic, but send only those messages pertaining to selected stations (identified by site-component-network codes). Currently used to send continuous waveform data to ATWC and UCB.
- wave_server -(the original wave_server) maintain a circular buffer of waveform data and send all data in a requested time range to a client over a socket. Used to send DST waveforms to Menlo Park's CUSP system.
- wave_serverIII, wave_serverIV - maintain a circular buffer of waveform data and send data from requested channels, requested time intervals to a client over a socket. Currently serves wave_viewers (electronic develocorder program on Windows desktop and laptop computers) and rsec2.
- vdl -send triggered waveform data to USNSN

### Programs/modules under development:

- rcv -adapt Dave Ketchum's rcv/station software into an Earthworm module. rcv/station receives triggered and/or continuous waveform data from USNSN, then passes it to an Earthworm-specific function which outputs it to a ring in Earthworm trace_buf format.
- rsec2 -given an event located by hypoinverse, request the waveforms of the closest N stations from a wave_server module, then produce a record-section in GIF-format.
- getdst24 -acquire continuous 24-bit digitally-telemetered seismic data from new DST stations. Data will be time-stamped in the field. Currently in the drawing-board stage.

### Our Additional Goals:

- Write better documentation of what we have.

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