Approximations to the Directivity Index
Abstract
Directivity indexes of three different underwater sound transducers have been measured or computed by five different methods: (1) theoretical calculations using piston area or line length, (2) beam-width measurement and theoretical calculation, (3) pattern measurement and graphical integration, (4) direct digital directivity index measuring system, and (5) diffuse-sound method. The results indicate that the directivity index of any ordinary transducer can be obtained from calculations based on known configurations and dimensions or beam-width measurements with a degree of reliability and accuracy that is no worse than any measurement technique and that, in most cases, elaborate measurements for determining directivity index are not justified.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1974
- Accession Number
- AD0778660
Entities
People
- Robert J. Bobber
Organizations
- United States Naval Research Laboratory