Optimum Depth of Propagation in Shallow Water
Abstract
A numerical simulation study was conducted to determine the receiver depth which would maximize the signal-to-wind noise ratio for one of several source depths in various shallow water environments. The environments were chosen to cover the full range typically found in shallow water: four sediment types ranging from fine sand to silty clay, three sound-speed profiles in the water column (isovelocity, positive gradient, and negative gradient), source depths within and below the gradient in the water sound-speed profile, and source frequencies in octaves from 50 to 800 Hz. For each case, a transmission- loss model and a wind-noise model were run. The results were then combined to yield a signal-to-noise level. By using a contouring technique, the data were reduced sufficiently to interpret the effects of the source depth, bottom type, velocity structure in the water column, and source frequency on the location of the optimum receiver depth. For frequencies above 200 Hz, the optimum depth was nearly independent of frequency and sediment type. In most cases, the optimum depth was equal to the source depth. In 75% of the cases the optimum depth was middepth or below. The location of the best signal-to-noise ratio (S/N) was in most cases independent of the wind-noise field.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 23, 1983
- Accession Number
- ADA132182
Entities
People
- David A. Gershfeld
- Frank Ingenito
Organizations
- United States Naval Research Laboratory