We thank the Department of Homeland Security for sponsoring J.S.A. and for the experimental deployment under Grant Award 2008-ST-061-ML0001. We also thank Portland State University for funding.
Journal of the Acoustical Society of America Express Letters
Underwater acoustics, Boats, Underwater acoustics -- Mathematics
Previous studies [Tiemann et al., J. Acoust. Soc. Am. 120, 2355–2365 (2006)] have reported the localization of marine mammals in 3-D from their clicks using multipath arrivals. Bathymetric variations were advantageously used to predict multipath arrival times with a raytracer. These arrivals are directly discernible from the time series for impulsive sources, such as whale clicks, but extension of the method to continuous broadband sources presents additional complications. By pulse compressing noise emitted from a small boat using two hydrophones,the hyperbolic direct-arrival ambiguity can be refined in both range and bearing. Acoustic-derived results are validated with target GPS measurements.
Gebbie, J., Siderius, M., McCargar, R., Allen, J. S., & Pusey, G. (2013). Localization of a noisy broadband surface target using time differences of multipath arrivals. Journal Of The Acoustical Society Of America, 134(1), EL77-EL83.