Jm. Ozard et al., MATCHED-FIELD PROCESSING IN A RANGE-DEPENDENT SHALLOW-WATER ENVIRONMENT IN THE NORTHEAST PACIFIC-OCEAN, IEEE journal of oceanic engineering, 21(4), 1996, pp. 377-383
This paper describes matched-field processing (MFP) of data collected
in shallow water off the western coast of Vancouver Island in the Nort
heast Pacific Ocean, The data mere collected from a vertical line arra
y (VLA) as part of the PACIFIC SHELF Trial carried out on the continen
tal shelf and slope during September 1993, Sensors in the 16-element V
LA were evenly spaced at depths between 90 and 315 m, while the sound
source was towed along radial paths or arcs, In this paper, we present
results of the analysis of data from a continuous wave (CW) source wh
ich was towed downslope at a depth of 30 m in water from 150 to 375 m
deep, In order to model the range-dependence of the acoustic propagati
on efficiently, the replica fields were calculated using the adiabatic
normal mode approximation, This approximation was considered appropri
ate for the bottom slopes of the environment, Using sparse bathymetric
data, a water sound speed profile and estimates of bottom properties,
MFP correlations on individual ambiguity surfaces were found to be gr
eater than 0.9 for the strongest signals, On account of environmental
mismatch, the source position could not be determined unambiguously fr
om most of the ambiguity surfaces even at high signal-to-noise ratios,
Nevertheless, when an Efficient Linear Tracker was applied to the amb
iguity surfaces to find tracks, the source track was recovered at both
low and high signal-to-noise ratios, This tracker performs the analys
is at a constant depth and reports the track with the highest estimate
d track signal-to-noise ratio.