Radar Pulse Compression and Electromagnetic Interference (EMI)
Abstract
The acoustical significance of ocean surface dynamics is well known. Motivation for establishing the causal relations between these two physical processes has both underwater acoustic system noise reduction and oceanographic remote sensing objectives. The goal has eluded investigators because of the complexity of both the acoustic and oceanographic mechanisms involved. The work discussed here continues progression in spatial scales by utilizing a relatively deep water basin (The Tongue of the Ocean, the Bahamas) in a quasi-controlled environment which made a broadband measurement (40 to 4000 Hz) of the vertical directional spectrum of the ambient acoustic field. The 1-year data base of directional spectrum are dominated by local (fetch limited) water surface conditions over a wide range of environmental conditions. While the exploratory nature of the experiment limited the amount of supporting meteorological and oceanographic measurements made, the results give additional credence to the role of entrapped air bubbles and bubble clouds in the generation of acoustic ambient. Sea surface-generated acoustics is shown to be dependent on a fundamental nondimensional variable describing the air-sea boundary process and the rate of energy dissipation caused by wave-breaking in the gravity wave equilibrium range.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 30, 1991
- Accession Number
- ADA236820
Entities
People
- Ching-tai Lin
Organizations
- United States Naval Research Laboratory