Low frequency digitization errors and a new method for zero baseline correction of strong-motion accelerograms

Abstract

A study of the random digitizing errors introduced by the operator indicates that these errors are relatively small in the doubleintegrated digital data up to a period of about 16 seconds for a typical accelerograph record. A new method is proposed for standard baseline correction of accelerograms. It is based on high-pass filtering of the uncorrected data. Unlike the parabolic baseline correction, the new method has well defined frequency transfer function properties which are largely independent of the record length.