Publications

Merchant, Bion J.; Rembold, Randy K.

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Rembold, Randy K.; Merchant, B.J.; Davis, Peter J.; Ebeling, Carl W.; Wilson, David L.; Ringler, Adam T.; Anthony, Robert E.

The Comprehensive Nuclear-Test-Ban Treaty mandates the four verification technologies to be used by the International Monitoring System (IMS) to monitor compliance to the Treaty. These technologies are seismic, hydroacoustic, infrasound, and radionuclide. Operational manuals for each of these technologies specify the requirements that equipment installed at IMS stations must meet for data from said stations to be accepted by the International Data Center. Following a model in which a revised set of infrasound sensor specifications and accompanying test procedures were developed in an international collaboration overseen by the Comprehensive Nuclear-Test-Ban Treaty Organization, the same process was recently followed for seismometers potentially of use by the IMS. This document, a product of that collaboration, defines key concepts and recommends test procedures to be followed to characterize broadband seismometers in a consistent and standardized way. Results from these test procedures can be used to verify that a seismometer meets the manufacturers stated specifications and IMS requirements. ACKNOWLEDGEMENTS The writers of this document would like to acknowledge Charles R. Hutt, John R. Evans, Fred Followill, Robert L. Nigbor, and Erhard Wielandt, the authors of the 2009 Guidelines for Standardized Testing of Broadband Seismometers and Accelerometers funded by the U.S. Department of Interior, on which this document is based. Although this document is limited in scope to seismometers and much of the document has been updated, the structure remains essentially the same.

Merchant, Bion J.; Rembold, Randy K.

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Merchant, Bion J.; Rembold, Randy K.; Slad, George W.

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Slad, George W.; Merchant, Bion J.; Rembold, Randy K.

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Rembold, Randy K.; Merchant, Bion J.

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Slad, George W.; Merchant, Bion J.; Rembold, Randy K.; Slad, George W.

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Rembold, Randy K.

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Slad, George W.; Merchant, Bion J.; Rembold, Randy K.; Knox, James M.; Williams, Michelle W.

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Merchant, Bion J.; Merchant, Bion J.; Rembold, Randy K.

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Merchant, Bion J.; Slad, George W.; Rembold, Randy K.; O'Brien, Edward O.; Kypta, Timothy K.

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Merchant, Bion J.; Rembold, Randy K.; Slad, George W.

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Merchant, Bion J.; Rembold, Randy K.

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Rembold, Randy K.

By means of the Antarctic Treaty, which all announced claimants have signed and ratified, no claims to territorial sovereignty shall be asserted while the Treaty is in force. The Treaty, which has been signed by 44 countries (May 2000), reserves the area south of 60 degrees south a zone for peaceful conduct of research.

Symons, Neill P.; Rembold, Randy K.; McDowell, Kyle D.; Merchant, Bion J.; Jones, Kyle R.

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Rembold, Randy K.

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Hart, Darren H.; Rembold, Randy K.

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Hart, Darren H.; Rembold, Randy K.

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Hart, Darren H.; Rembold, Randy K.

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Rembold, Randy K.

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Hart, Darren H.; Rembold, Randy K.; Parks, Harold V.

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Hart, Darren H.; Parks, Harold V.; Rembold, Randy K.

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Hart, Darren H.; Rembold, Randy K.

Sandia National Laboratories has tested and evaluated Geotech SMART24BH borehole data acquisition system with active Fortezza crypto card data signing and authentication. The test results included in this report were in response to static and tonal-dynamic input signals. Most test methodologies used were based on IEEE Standards 1057 for Digitizing Waveform Recorders and 1241 for Analog to Digital Converters; others were designed by Sandia specifically for infrasound application evaluation and for supplementary criteria not addressed in the IEEE standards. The objective of this work was to evaluate the overall technical performance of two Geotech SMART24BH digitizers with a Fortezza PCMCIA crypto card actively implementing the signing of data packets. The results of this evaluation were compared to relevant specifications provided within manufacturer's documentation notes. The tests performed were chosen to demonstrate different performance aspects of the digitizer under test. The performance aspects tested include determining noise floor, least significant bit (LSB), dynamic range, cross-talk, relative channel-to-channel timing, time-tag accuracy/statistics/drift, analog bandwidth.

Rembold, Randy K.; Harris, James M.

Sandia National Laboratories has tested, evaluated and reported on the Geotech Smart24 data acquisition system with active Fortezza crypto card data signing and authentication in SAND2008-. One test, Input Terminated Noise, allows us to characterize the self-noise of the Smart24 system. By computing the power spectral density (PSD) of the input terminated noise time series data set and correcting for the instrument response of different seismometers, the resulting spectrum can be compared to the USGS new low noise model (NLNM) of Peterson (1996), and determine the ability of the matched system of seismometer and Smart24 to be quiet enough for any general deployment location. Four seismometer models were evaluated: the Streckeisen STS2-Low and High Gain, Guralp CMG3T and Geotech GS13 models. Each has a unique pass-band as defined by the frequency band of the instrument corrected noise spectrum that falls below the new low-noise model.

Herrington, Preston B.; Rembold, Randy K.; Harris, James M.; Kromer, Richard P.; Harris, James M.

All stations planned for the International Monitoring System (IMS) must be certified by the Provisional Technical Secretariat (PTS) prior to acceptance to ensure that the monitoring stations initially meet the required specifications. Working Group B of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty has established requirements for the quality, availability, and surety of data received at the International Data Centre (IDC). These requirements are verified by the PTS during a 3-component process that includes initial station assessment, testing and evaluation, and certification. Sandia National Laboratories has developed procedures, facilities, and tools that can be used to assist in evaluating IMS stations for compliance with certification requirements. System evaluation includes station design reviews, component testing, and operational testing of station equipment. Station design is evaluated for security and reliability considerations, and to ensure that operational procedures and documentation are adequate. Components of the station are tested for compliance with technical specifications, such as timing and noise levels of sampled data, and monitoring of tamper detection equipment. Data sent from the station in an IMS-standard format (CD-1 or IMS-1) are analyzed for compliance with the specified protocol and to ensure that the station data (sensor and state-of-health) are accurately transmitted. Data availability and authentication statistics are compiled and examined for problems.