2008.73: Forward and Inverse Problems in Towed Cable Hydrodynamics
2008.73: Nick Polydorides, Eskild Storteig and William Lionheart (2008) Forward and Inverse Problems in Towed Cable Hydrodynamics.
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This paper addresses the problem of reconstructing the velocities of t he ocean currents impinging on a towed streamer cable during an oﬀshore seismic survey. This study considers a two-dimensional model describing the motion of a ﬂexible, inextensible cable in the presence of hydrodynamic drag forces in an in compressible ﬂuid. In the ﬁrst part the forward model is introduced and then sol ved to yield the cable’s velocity, curvature and tension in the knowledge of the towing vessel motion and the hydrodynamic loads applied. In sequence, we formul ate the inverse problem of inferring the ocean current velocities from discrete samples of the cable’s shape and tension and show that this is rank deﬁcient and ill-posed. In approaching the inverse problem a numerically stable algorithm is adopted based on generalized Tikhonov regularization, in the context of robust diﬀerentiation of discrete noisy signals. In order to demonstrate the practical performance of the scheme, some examples of ocean current reconstructions obtain ed using simulated noisy data are presented.
|Item Type:||MIMS Preprint|
|Uncontrolled Keywords:||towed seismic array, ocean current, inverse problem|
|Subjects:||MSC 2000 > 34 Ordinary differential equations|
MSC 2000 > 76 Fluid mechanics
PACS 2003 > 89 Other areas of applied and interdisciplinary physics
|Deposited By:||Prof WRB Lionheart|
|Deposited On:||15 July 2008|