UNIVERSITY OF SOUTHERN CALIFORNIA Department of Civil Engineering FROM SEISMIC SOURCE TO STRUCTURAL RESPONSE: CONTRIBUTIONS OF PROFESSOR

The modern techniques for digitization of strong-motion accelerograms and subsequent data processing were first developed in the late 1960s and early 1970s, at which time the only available digitization technology was semi-automatic hand digitization. Following the development of image processing technologies in the early 1970s, an automatic digitization and data processing system, driven by a mini-computer, was developed by Trifunac and Lee. The currently used digitization technology is based on personal computers and flat bed digital scanners, which appeared respectively in the early and late 1980s. The data processing part has been continuously evolving, thus improving the performance of the entire system. This paper presents a review of the developments in hardware and software for digitization of strong-motion accelerograms, data processing and data dissemination. In the 1980s, digital strong motion accelerographs became commercially available, and currently all new deployments are digital. However, it takes time to record a large number of strong motion accelerograms, and as of now, by far, most of the strong motion data has been recorded in analog form.