Accession Number : ADP204504

Title :   An Automated Rayleigh Wave Detection Algorithm,

Corporate Author : SANDIA NATIONAL LABS ALBUQUERQUE NM

Personal Author(s) : Chael, Eric P.

PDF Url : ADP204504

Report Date : 14 AUG 1995

Pagination or Media Count : 8

Abstract : The desire to operate denser networks in order to monitor seismic activity at lower thresholds leads to greater emphasis on automated data processing. An algorithm for detecting and characterizing long-period Rayleigh wave arrivals has been developed and tested. The routine continuously monitors all directions of approach to a station, in a manner similar to beamforming. The detector is based on cro ss-powers between the Hilbert-transformed vertical and rotated horizontal signals, so it is sensitive to both the power and polarization properties of the three-component wavefield. Elliptically polarized Rayleigh arrivals are enhanced, while linearly polarized Love waves and body phases are suppressed. A test using one month of data from station ANMO demonstrated that this technique can with high reliability detect Rayleigh arrivals which would be visible to an analyst. The measured arrival times and azimuths are accurate enough to permit automated association of the detections to events in a bulletin.

Descriptors :   *SEISMIC DETECTION, *SEISMIC WAVES, *ARMS CONTROL, *NUCLEAR EXPLOSION DETECTION, *RAYLEIGH WAVES, ALGORITHMS, SYMPOSIA, SURFACE WAVES, AUTOMATION, VERIFICATION, MONITORING, UNDERGROUND EXPLOSIONS, NUCLEAR EXPLOSION TESTING, BEAM FORMING, SEISMIC DISCRIMINATION, TREATIES, EARTHQUAKES, AZIMUTH, LOVE WAVES, ALEUTIAN ISLANDS, SOUTH PACIFIC OCEAN.

Subject Categories : Government and Political Science
      Seismology
      Seismic Detection and Detectors
      Nuclear Weapons

Distribution Statement : APPROVED FOR PUBLIC RELEASE