In Water Demonstration of Monochromatic Acoustic Mode Generation in Shallow Water
Abstract
LONG-TERM GOALS. To develop active acoustic methods which improved our ability to efficiently monitor and characterize the acoustic propagation characteristics of a shallow water environment. OBJECTIVE. The technical objective of this effort is to demonstrate the feasibility of generating an acoustic field at a desired location which is composed of a single selected mode in a range and temporally varying shallow water environment. APPROACH. A vertical array of acoustic sources is used to control the vertical structure of the acoustic field. The resulting field is received at a vertical array of hydrophones (the feedback array located at the point at which a single acoustic mode is desired) a short distance from the source array. This received field is used as the input to a feedback control algorithm which will adjust the signals transmitted by the source array. These signals are adjusted so that the acoustic field as received at the feedback array is composed of only the desired mode. This single mode field will then propagate down range from the feedback array and can be monitored at other points. The modal structure of the received field at these other points can be used to characterized the modal coupling behavior of the environment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1997
- Accession Number
- ADA635112
Entities
People
- James C. Preisig
- Mark P. Johnson
Organizations
- Woods Hole Oceanographic Institution