An unattended seismological observatory

Sandia Laboratory is developing and testing prototype equipment to continuously record outputs from three short-period and three long-period unattended seismometers for up to 120 days. Timing accuracy will be within 0.1 second throughout the record period. The system will be capable of recording a 70 decibel signal range. As much as 42 decibel attenuation can also be applied to each short-period data channel by an automatic gain control system to compensate for high levels of background noise. Concurrent with the development of the recording system, a playback system is being developed and tested which will convert the recorded data and timing signals to the standard Vela Uniform tape format. According to present schedules, the systems should be fully evaluated in the laboratory and in the field by the beginning of 1967.