A modal/WKB inversion method for determining sound speed profiles in the ocean and ocean bottom
Casey, Kevin D.
MetadataShow full item record
LocationGulf of Mexico
Two approaches to determining the ocean sound speed profile using measured acoustic modal eigenvalues are examined. Both methods use measured eigenvalues and mode dependent assumed values of the WKB phase integral as input data and use the WKB phase integral as a starting point for relating the index of refraction to depth. Inversion method one is restricted to monotonic or symmetric sound speed profiles and requires a measurement of the sound speed at one depth to convert the index of refraction profile to a sound speed profile. Inversion method two assumes that the sound speed at the surface and the minimum sound speed in the profile are known and is applicable to monotonic profiles and to general single duct sound speed profiles. For asymmetric profiles, inversion method two gives the depth difference between two points of equal sound speed in the portion of the profile having two turning points, and in the remainder of the profile it gives sound speed versus depth directly. A numerical implementation of the methods is demonstrated using idealized ocean sound speed profiles numerical experiments used to test the performance of the inversions using noisy data. The two methods are used to determine the sediment sound speed profiles in two shallow water waveguide models, and inversion method one is used to find the sediment sound speed profile using data from an experiment performed in the Gulf of Mexico.
Submitted in partial fulfillment of the requirements for the degree of Ocean Engineer at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1988
Showing items related by title, author, creator and subject.
An inverse method for obtaining the attenuation profile and small variations in the sound speed and density profiles of the ocean bottom Rajan, Subramaniam D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1985-05)The acoustic properties of marine sediments have a direct effect on the propagation of sound in the ocean. In the frequency range of interest (50 - 500 Hz) the sediment can be modelled as a fluid. Assuming horizontal ...
Njeru, James Murwanthanje (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-02)An average sound speed profile over a 1000 km section of the northeast Pacific ocean is obtained using Ocean Acoustic Tomography, from data acquired during the 1987 SVLA experiment on a long (900 m) 120 hydrophone vertical ...
Souza, Luiz Alberto Lopes de (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-02)This thesis investigates the application of acoustic measurements in the deep and shallow ocean to infer the sound velocity profile (svp) in the seabed. For the deep water ocean, an exact method based on the Gelfand-Levitan ...