Electrical and Computer Engineering ETDs

Publication Date

12-19-1974

Abstract

Four methods of data reconstruction were applied to actual seismometer data with inherent low frequency linear distortion, for relative evaluation and comparison. An electronic system inverse circuit, an impulse invariant Z transform inverse system model, time domain decon­volution, and fast Fourier transforms were the methods used. It was found that from the standpoints of ease of application, computer core and CPU requirements, and reconstruction quality, the electronic inverse circuit and time domain deconvolution would probably be the reconstruction options favored by most seismometer users. Of these two methods, time domain deconvolution exhibited slightly better reconstruction quality than did the inverse circuit. The impulse invariant Z transform reconstruction method performed fairly well but was not capable of handling output reconstructions of extremely slow motion inputs. The fast Fourier transform reconstruction required tremendous amounts of computer core and CPU time, and required total reconstruction over the entire test transient output interval. The fast Fourier transform reconstruction also exhibited large D.C. shifts. The reason for this was determined and explained. In addition to the evaluation of the four reconstruction methods, a new method called general time domain deconvolution or arbitrary in­put invariant reconstruction was found using Z transform theory. This method received limited testing but appears to have a good potential for data reconstruction.

Document Type

Thesis

Language

English

Degree Name

Electrical Engineering

Level of Degree

Masters

Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Joseph Thomas Cordaro Jr

Second Committee Member

Larry Wayne Bickle

Third Committee Member

Arnold Herman Koschmann

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