Transfer functions for the seismic research observatory seismograph system

Abstract

Transfer functions are given for all basic elements of the Seismic Research Observatory (SRO) seismograph system. These include the seismometer, response shaping filters, and anti-alias filters. With these transfer functions the amplitude and phase responses can be calculated at any frequency by the evaluation of a ratio of polynomials in s = iω. Amplitude and phase response plots and impulse responses are given for the most important overall transfer functions. In addition, long- and short-period group delays have been calculated by numerical differentation of phase responses. In the long-period case a simple polynomial approximation to the group delay is given as an aid in interpretation of data. The transfer functions are exact and follow from the integral design of the system.