Accession Number:

AD0743065

Title:

The Fast Field Program (FFP) and Attenuation Loss in Hudson Bay

Descriptive Note:

Technical rept.

Corporate Author:

NAVAL UNDERWATER SYSTEMS CENTER NEWPORT RI

Personal Author(s):

• DiNapoli, Frederick R.
• Powers, Mary R.

Report Date:

1972-04-19

Pagination or Media Count:

43.0

Abstract:

The Fast Field Program FFP was developed to provide rapid, accurate, propagation-loss predictions for a generalized environmental model. This report demonstrates the utility of the FFP, in a different capacity, as a research tool to investigate the sound attenuation in a water column. Hudson Bay was selected as the area of application because the results of propagation experiments conducted there during August 1970 were available and interesting. The experimentally determined values of the attenuation coefficient for the frequency band 315 to 1600 Hz were found to exceed the values that would be predicted from existing formulas based on empirical relationships. The possibility that this anomalous behavior could have been due to energy leakage into the bottom is examined, and the values of the attenuation coefficient determined from the FFP analysis are compared with experimental results.

Descriptors:

• *SOUND TRANSMISSION
• *UNDERWATER SOUND
• VELOCITY
• MATHEMATICAL MODELS
• ANOMALIES
• OCEAN BOTTOM
• UNDERWATER SOUND SIGNALS
• HUDSON BAY
• ACOUSTIC PROPERTIES
• LOW FREQUENCY
• ATTENUATION
• SHALLOW WATER
• MATHEMATICAL PREDICTION

Subject Categories:

• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE