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Title: United States Geological Survey (USGS) FM cassette seismic-refraction recording system

Abstract

In this two chapter report, instrumentation used to collect seismic data is described. This data acquisition system has two parts: (1) portable anolog seismic recorders and related ``hand-held-testers`` (HHT) and (2) portable digitizing units. During the anolog recording process, ground motion is sensed by a 2-Hz vertical-component seismometer. The voltage output from the seismometer is split without amplification and sent to three parallel amplifier circuit boards. Each circuit board amplifiers the seismic signal in three stages and then frequency modulates the signal. Amplification at the last two stages can be set by the user. An internal precision clock signal is also frequency modulated. The three data carrier frequencies, the clock carrier frequency, and a tape-speed compensation carrier frequency are summed and recorded on a recorded on a cassette tape. During the digitizing process, the cassette tapes are played back and the signals are demultiplexed and demodulated. An anolog-to-digital converter converts the signals to digital data which are stored on 8-inch floppy disks. 7 refs., 19 figs., 6 tabs.

Authors:
Publication Date:
Research Org.:
Geological Survey, Menlo Park, CA (United States)
OSTI Identifier:
137903
Report Number(s):
USGS-OFR-88-570
ON: DE91001644; TRN: 90:035322
DOE Contract Number:  
AI08-78ET44802
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1988
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 58 GEOSCIENCES; SEISMIC DETECTORS; OPERATION; PORTABLE EQUIPMENT; ANALOG-TO-DIGITAL CONVERTERS; RECORDING SYSTEMS; MEMORY DEVICES; CALIBRATION; SEISMIC WAVES; DATA ACQUISITION SYSTEMS; US GS; Yucca Mountain Project

Citation Formats

Murphy, J M. United States Geological Survey (USGS) FM cassette seismic-refraction recording system. United States: N. p., 1988. Web. doi:10.2172/137903.
Murphy, J M. United States Geological Survey (USGS) FM cassette seismic-refraction recording system. United States. doi:10.2172/137903.
Murphy, J M. Sat . "United States Geological Survey (USGS) FM cassette seismic-refraction recording system". United States. doi:10.2172/137903. https://www.osti.gov/servlets/purl/137903.
@article{osti_137903,
title = {United States Geological Survey (USGS) FM cassette seismic-refraction recording system},
author = {Murphy, J M},
abstractNote = {In this two chapter report, instrumentation used to collect seismic data is described. This data acquisition system has two parts: (1) portable anolog seismic recorders and related ``hand-held-testers`` (HHT) and (2) portable digitizing units. During the anolog recording process, ground motion is sensed by a 2-Hz vertical-component seismometer. The voltage output from the seismometer is split without amplification and sent to three parallel amplifier circuit boards. Each circuit board amplifiers the seismic signal in three stages and then frequency modulates the signal. Amplification at the last two stages can be set by the user. An internal precision clock signal is also frequency modulated. The three data carrier frequencies, the clock carrier frequency, and a tape-speed compensation carrier frequency are summed and recorded on a recorded on a cassette tape. During the digitizing process, the cassette tapes are played back and the signals are demultiplexed and demodulated. An anolog-to-digital converter converts the signals to digital data which are stored on 8-inch floppy disks. 7 refs., 19 figs., 6 tabs.},
doi = {10.2172/137903},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1988},
month = {12}
}