An Empirical Match-Filter Study with Central Asian and South Pacific Events

Abstract

Two suites of events, one in the Tonga Islands, and the other in the Hindu Kush, were match filtered to determine relative enhancement in signal-to- noise ratio achieved by various procedures. It was found that match-filter S/N enhancement depends very little on the proximity of the reference event used as a match filter for distances as great as 600 km. For both regions, one event with high S/N ratio performed as well as many closer events in match filtering. Pre-whitening the real signals from zero to the folding frequency before using them as matched filters resulted in serious S/N decreases on the output unless band-pass filtering was applied simultaneously to the signal band, approximately 15 to 50 seconds. A linear chirp waveform worked as well as a real waveform for the Asian events, but it was inferior to real waveforms in the Pacific.

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Document Details

Document Type
Technical Report
Publication Date
Jun 30, 1971
Accession Number
AD0740424

Entities

People

  • David H. Von Seggern

Organizations

  • Teledyne Technologies

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Air Force
  • Amplitude
  • Chirp Filters
  • Contracts
  • Detection
  • Dispersing
  • Dispersions
  • Filters
  • Filtration
  • Frequency
  • Group Velocity
  • Phase Velocity
  • Rayleigh Waves
  • Surface Waves
  • Virginia
  • Waveforms
  • Waves

Readers

  • Image Processing and Computer Vision.
  • Seismology