REMOTE SETUP AND CALIBRATION OF SEISMIC EQUIPMENT WITH AUTOMATIC EVENT DETECTION AND RECORDING OF SEISMIC EVENTS

Abstract

The Nevada Test Site Seismic Network, designed and operated by EG&G Energy Measurement, Inc. for Sandia National Laboratories, consists of five remote stations and one control point station. The system converts analog signals from five seismometers at each station to digital signals and multiplexes the data with status information for transmission over voice-grade telephone circuits to the control point at the Nevada Test Site. Intelligent modems provide automatic line equalization, transmission link diagnostics, and loopback testing. A microprocessor at the remote stations periodically refreshes the seismometer system gain settings to ensure data accuracy. The remote stations operate unattended and receive commands for setup and status check from the control point. The control point station utilizes a Digital Equipment Corporation (DEC) LSI-11/23 to perform event detection on the five data streams and automatically records up to ninety minutes of event data per station. Planned upgrades include replacing the LSI-11/23 with a DEC MicroVAX-II and implementing dialup capability to verify station status.