Detectability of low-level broad-band signals using adaptive matched-field processing with vertical aperture arrays

Alerted detection of low-level broad-band signals using adaptive matched-field processing (MFP) is illustrated in results from a shallow-water experiment carried out 12 km west of Point Loma, CA, in 200-m water of complex bathymetry. A 118-m vertical line array was deployed next to an identical line array tilted at 45 degrees. Array gain and signal excess for each of the arrays with linear and adaptive broad-band MFP is measured and compared using a low-level (118 dB//1 /spl mu/Pa/sup 2//Hz) broad-hand signal from a towed source. Surface/submerged classification was achieved at the minimum detectable level due to the depth resolution obtained with MFP. The results are compared qualitatively with adaptive plane-wave beamforming on a horizontal line array deployed nearby.