Improvement of three dimensional acoustic field estimation using tomographic reconstructions of the ocean
Rowe, Elizabeth Anne
MetadataShow full item record
In order to determine the efficacy of tomographic reconstructions of the ocean sound speed structure in improving acoustic field predictions for source localization, a 150 km by 350 km volume of ocean 3000 meters deep was synthetically modeled to be similar to the Gulf Stream system, including an eddy and a front. The features were Gaussian, with the eddy's maximum sound speed perturbation being 10ms-1 and the front's maximum perturbation 15ms-1. Two vertical slices through this system were inverted in a synthetic tomography experiment using linear optimal estimation theory. Inversions were also performed using XSV and satellite sea surface temperature data. Gaussian fits to the reconstructed features were constructed for use with a three dimensional raytrace program (HARPO). Three dimensional rays were propagated both through the reconstructions and the original model. Travel time versus intensity (transmission loss) for the eigenrays was used as a basis for intercomparison. Tomographic results showed good reconstruction for a first iteration of the inversion, but inadequate vertical resolution. Iterations and the use of more refractive eigenrays are needed for improvement of the reconstruction, especially for the front. Reconstructed results for the acoustic field should improve conventional beamforming, but are probably inadequate for matched field processing.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1988
Showing items related by title, author, creator and subject.
Slavinsky, Mark; Bogolubov, Boris; Alelekov, Igor; Pigalov, Konstantin; Spiesberger, John L.; Boutin, Paul (Woods Hole Oceanographic Institution, 1993-02)A compact electromagnetic monopole source, requiring pressure equalization, was evaluated at the Naval Underwater Systems Center at Lake Seneca during July 1992 by scientists from the Institute of Applied Physics of the ...
Physically constrained maximum likelihood (PCML) mode filtering and its application as a pre-processing method for underwater acoustic communication Papp, Joseph C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-09)Mode filtering is most commonly implemented using the sampled mode shape or pseudoinverse algorithms. Buck et al placed these techniques in the context of a broader maximum a posteriori (MAP) framework. However, the MAP ...
Bohner, Christopher George (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2003-09)A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically ...