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Similarities in the behavior of diverse animal species that form large groups have motivated attempts to establish general principles governing animal group behavior. It has been difficult, however, to make quantitative measurements of the temporal and spatial behavior of extensive animal groups in the wild, such as bird flocks, fish shoals, and locust(More)
The low-frequency target strength of shoaling Atlantic herring (Clupea harengus) in the Gulf of Maine during Autumn 2006 spawning season is estimated from experimental data acquired simultaneously at multiple frequencies in the 300-1200 Hz range using (1) a low-frequency ocean acoustic waveguide remote sensing (OAWRS) system, (2) areal population density(More)
The scintillation statistics of broadband acoustic transmissions are determined as a function of signal bandwidth B, center frequency f(c), and range with experimental data in the New Jersey continental shelf. The received signal intensity is shown to follow the Gamma distribution implying that the central limit theorem has led to a fully saturated field(More)
The matched filter enables imaging with high spatial resolution and high signal-to-noise ratio by coherent correlation with the expected field from what is assumed to be a discrete scatterer. In many physical imaging systems, however, returns from a large number of randomized scatterers, ranging from thousands to millions of individuals, are received(More)
INTRODUCTION Fish populations often comprise the largest biomass component in a productive marine ecosystem. They typically play an essential role in inter-trophic energy transport (Cury et al. 2001), and serve as a mainstay for human consumption comprising roughly 16% of the animal protein consumed by the world's population (FAO 1997). Despite their(More)
An analytic model is developed for scattering from random inhomogeneities in range-dependent ocean waveguides using the Rayleigh-Born approximation to Green's theorem. The expected scattered intensity depends on statistical moments of fractional changes in compressibility and density, which scatter as monopoles and dipoles, respectively, and the coherence(More)
This study aimed to evaluate the potential association with anthropometry and upper-body pulling strength with sprint kinematics of competitive surfers. Ten competitive male surfers (23.9 ± 6.8 years, 177.0 ± 6.5 cm, 72.2 ± 2.4 kg) were assessed for stature, mass, arm span, ∑ 7 site skinfold thickness, pronated pull-up strength, and sprint paddling(More)
An ocean acoustic waveguide remote sensing system can instantaneously image and continuously monitor fish populations distributed over continental shelf-scale regions. Here it is shown theoretically that the areal population density of fish groups can be estimated from their incoherently averaged broadband matched filtered scattered intensities measured(More)
The probability distribution of ocean-acoustic broadband signal energy after saturated multipath propagation is derived using coherence theory. The frequency components obtained from Fourier decomposition of a broadband signal are each assumed to be fully saturated with energy spectral density that obey the exponential distribution with 5.6 dB standard(More)
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. The low-frequency target strength of shoaling Atlantic herring ͑Clupea(More)