Chapter 2. Introduction

Network Trigger is an application used alongside Scream! to monitor a network of sensors and raise an alarm should more than a set number of instruments in the network exceed pre-set levels of seismic activity.

Any GCF data collected by Scream can be used as an input to Network Trigger, including data from both locally connected instruments and remote instruments connected via the Internet or any private network.

The data are sent to a number of configurable processor modules, each of which calculates a resultant value, such as peak ground acceleration (PGA), and compares it to a programmable threshold in order to determine whether a notable event has occurred. Should an event occur, notifications can be sent via email, SMS text or the operation of a relay (when used with optional relay interface, CMG-STA-RLY0).

The Network Trigger application features:

• PGA (Peak Ground Acceleration), PGV (Peak Ground Velocity) and SI (Spectral Intensity) calculations

• High-pass and low-pass filtering

• Independent trigger levels

• Horizontal and tri-axial resultants: calculation and triggering

• Notifications via

  • Email

  • SMS text

  • Relay operation

• Runs under Windows (9x/NT/2000/XP, Vista, 7, 8)