Experimental Study of the Radiation Properties of a Parametric Fog Horn.
Abstract
An experimental study of the radiation properties of a parametric fog horn was conducted using a 4 unit x 5 unit horn driver array as the primary source. The horn was operated as two separate 10-unit acoustic arrays each transmitting one primary frequency. The frequency combinations studied were 4240-5520Hz and 4960-5520Hz. The acoustic properties of the parametric array were observed for both frequency combinations. Source levels were varied between 122dB re 20muPA and 134dB re 20muPA at 1 meter to study the transition from absorption limited performance to saturation limited performance. Results consistent with the predictions of Moffett and Mellen (JASA 61, 325-337 (1977)) for the source level of the difference frequency beam and saturation broadening of the difference frequency beam were observed. The horn was also operated as a single array with all units radiating both primary frequencies. Equivalent results were obtained. A discussion of fog signaling applications is included. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1979
- Accession Number
- ADA081148
Entities
People
- Stephen Edward Trenchard
Organizations
- Naval Postgraduate School