Digital Seismic Logger “Ermak-5”. Experience of Development and Implementation

Abstract

The necessary conditions for development and successful implementation of a digital seismic logger “Ermak-5” are considered. A short review of similar technical solutions for modern seismological monitoring systems is given, and qualitative comparative analysis is fulfilled. Technical and operational requirements for development of the logger are substantiated. The results of laboratory and field experiments are reported for confirmation of key specifications of this device. The special attention is paid to conformity of the amplitude–frequency characteristics of the logger to reference analogues. Different types of seismometers were used for comparative testing. Description of hardware–software implementation of the flexible power management system of the logger is given. It helps to decrease power consumption to about 300 mW when the recording is made through six channels. The logger can be used for long-term recording with autonomous power supply sources. The core of time in the logger is developed on the basis of special algorithms to reach technological maximum for inner clock synchronization accuracy using the GPS/GLONNAS systems (hundreds of nanoseconds) and NTP-services (dozens of microseconds). Details of time synchronization algorithms are examined, and a description of experimental laboratory and field setup for time synchronization accuracy is given. The LCD screen of the logger is very important for effective operation. Information about time, some logger parameters, and waveform in different modes appears at the display. The experience of implementation at different seismic monitoring facilities is generalized, and it is taken into account in the revision process of the logger project.