SeaBED Presentations

Spectral Libraries of Submerged Biotopes for Benthic Mapping in Southwestern Puerto Rico

Carmen C. Zayas-Santiago — Wed, 16 Dec 2009 13:02:54 PST

The quantitative characterization of the submerged biotopes of Enrique Reef, southwestern Puerto Rico, requires atmospheric and water column corrections of satellite data before performing classification algorithms. The Lyzenga (1978) method was used for deriving three depth-invariant bands based on the visible bands of IKONOS imagery. The spectral reflectance properties of corals, seagrasses, gorgonians, sponges, sand and other benthic components were obtained in situ by a GER 1500 spectroradiometer and used to create a coral reef spectral library. The spectral properties of the submerged biotopes provide a measure of the variability of these targets, the degree at which they could be...

Statistics of broadband transmissions through a range-dependent fluctuating ocean waveguide

Mark Andrews — Wed, 16 Dec 2009 13:02:54 PST

Acoustic signals transmitted through an ocean waveguide are temporally and spatially varying due to multimodal interference and effects such as internal waves. Estimating parameters of sonar, the environment and scatterers requires a statistical approach that incorporates medium uncertainties into the signal analysis. Short duration broadband pulses were transmitted from a moored source array and measured by a towed horizontal receiving array at varying ranges from the source. The ping-to-ping fluctuations in the measured acoustic data are a result of changes in the waveguide modal intereference structure due to both motion of the array and presence of time dependent random internal...

SeaBED: A Laboratory and Field Test Environment for the Validation of Coastal Hyperspectral Image Analysis Algorithms

James Goodman — Wed, 16 Dec 2009 13:02:53 PST

The University of Puerto Rico at Mayaguez (UPRM), one of the core academic partners in the NSF sponsored Bernard M. Gordon Center for Subsurface Sensing and Imaging Systems (Gordon- CenSSIS), is developing algorithms using hyperspectral, multispectral and other sensing modalities to extract subsurface information in aquatic environments. As part of this effort, UPRM has created SeaBED, an algorithm validation testbed which is composed of three different analysis systems: a small laboratory based tank, a larger outdoor tank and a field site located on a nearby reef in southwest Puerto Rico. The main objective of SeaBED is to collect multiple levels...

SeaBED: A Laboratory and Field Test Environment for the Validation of Coastal Hyperspectral Image Analysis Algorithms

James Goodman — Wed, 16 Dec 2009 13:02:53 PST

The University of Puerto Rico at Mayaguez (UPRM), one of the core academic partners in the NSF sponsored Center for Subsurface Sensing and Imaging Systems (CenSSIS), is developing algorithms using hyperspectral, multispectral and other sensing modalities to extract subsurface information in aquatic environments. As part of this effort, UPRM has created SeaBED, an algorithm validation testbed which is composed of three different analysis systems: a small laboratory based tank, a larger outdoor tank and a field site located on a nearby reef in southwest Puerto Rico. The main objective of SeaBED is to collect multiple levels of image, field and...

Calibrated bistatic Rayleigh-born bottom reverberation model for fluctuating range-dependent continental shelf environments

Ameya Galinde — Wed, 16 Dec 2009 13:02:52 PST

Analytic and numerical models are developed for reverberation from volumetric inhomogeneities in the sea bottom in range dependent ocean waveguides using the Rayleigh-Born approximation to Green's theorem. The expected reverberation intensity depends on the statistical moments of the fractional changes in compressibility and density, which scatter like monopoles and dipoles respectively, and the coherence volume of the inhomogeneities. The model is calibrated using data acquired with a long range sonar on the New Jersey continental shelf during the 2003 Main Acoustic Experiment of the ONR Geoclutter Program. An approach for distinguishing moving clutter from statistically stationary background reverberation in long...