Publications

Sandia National Laboratories has continued to evaluate the performance of infrasound sensors that are candidates for use by the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty Organization. The performance criteria against which these sensors are assessed are specified in ``Operational Manual for Infra-sound Monitoring and the International Exchange of Infrasound Data''. This presentation includes the results of efforts concerning two of these sensors: (1) Chaparral Physics Model 5; and (2) CEA MB2000. Sandia is working with Chaparral Physics in order to improve the capability of the Model 5 (a prototype sensor) to be calibrated and evaluated. With the assistance of the Scripps Institution of Oceanography, Sandia is also conducting tests to evaluate the performance of the CEA MB2000. Sensor models based on theoretical transfer functions and manufacturer specifications for these two devices have been developed. This presentation will feature the results of coherence-based data analysis of signals from a huddle test, utilizing several sensors of both types, in order to verify the sensor performance.

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.