Array element localization for towed marine seismic arrays

This paper presents an approach to array element localization (AEL) for tow ed marine seismic arrays based on regularized inversion of direct and botto m-reflected acoustic ray travel times picked from recorded seismic sections . Depth-sensor measurements at a number of points along the array are inclu ded as a priori estimates (with uncertainties) in the inversion. The smooth est array shape consistent with the acoustic data and prior estimates is de termined by minimizing the array curvature or roughness. A smooth array sha pe is physically reasonable; in addition, minimizing curvature provides a p riori information about the correlation between hydrophone positions that a llows the estimation of both the offset and depth of hydrophones that recor d only one (or even no) acoustic arrival due to the shadowing effects of wa ter-column refraction or reflection from arbitrary bathymetry. The AEL inve rsion is applied to a 102-sensor, 1.2-km towed array to correct receiver po sitions in the seismic velocity analysis of a seabed gas hydrate survey. (C ) 2001 Acoustical Society of America.