Special Data Collection Systems.
Final rept. Aug 73-Oct 77,
TELEDYNE GEOTECH GARLAND TEX
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Work performed under Project T4703, Special Data Collection Systems, is described. Under the primary data collection task five portable seismograph systems were routinely operated at ten sites during the period from early 1975 through September 1977. Three additional systems were placed in operation in May and June 1977, and also remained operational through the contract period. The systems were operational for a total of 157 team months. Three special projects were completed under the program. In the first, the Model 36000 Borehole Seismometer KS-36000 was modified and tested for operation in boreholes up to 3000 meters deep. The modified unit was operated at a Wyoming site along a shallow borehole KS-36000 in order to determine the effects of depth on long-period signals. In another study, various techniques for detecting tunnels were investigated and field measurements were made. Finally, a study was made to determine the cause of unexplained noise on the KS-36000 instrument and to develop techniques for eliminating it. The eleven portable seismograph systems were modified as necessary to meet the requirements of the various tasks. Digital recording capability was included for five systems with the development of a digital data acquisition system. Filteramplifier systems were built for operation of three KS-36000 systems in place of the normal complement of surface seismometers. In general, the portable seismograph systems have continued to be a versatile and reliable means of collecting seismic data for research purposes.