RESEARCH PROGRAM IN ACOUSTIC REVERBERATION.

Abstract

In experiments in the Straits of Juan de Fuca, north of Seattle, Washington, sequential reverberation records were produced using pulsed continuous wave signals and a vertically-oriented, bottom-mounted, narrow-beam transducer. Several-hundred-pulse sequences were transmitted on the hour for 250 consecutive hours. The resulting reverberation was demodulated in quadrature and recorded on analog tape. The tapes were returned to the laboratory and digitized. Estimates of data parameters were then obtained using ensemble averaging techniques and the behavior of the estimates as a function of time was studied. Special attention was given to the determination of probability density functions, detection of environmental nonstationarity by testing the data for statistical inhomogeneity, and isolation of spatial-temporal patterns in the volume back-scattering strengths. Volume scattering strengths for the whole 250-hour period were obtained as a by-product of the latter activity. Diurnal variations as well as higher frequency space-time changes are clearly indicated. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 14, 1970
Accession Number
AD0705630

Entities

People

  • Robert L. Swarts

Organizations

  • Honeywell International, Inc.

Tags

DTIC Thesaurus Topics

  • Continuous Waves
  • Detection
  • Diurnal Variations
  • Frequency
  • Mathematics
  • Probability
  • Probability Density Functions
  • Reverberation
  • Scattering
  • Sequences
  • Transducers

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Oceanography.
  • Statistical inference.

Technology Areas

  • Space