Apparatus and methods for reducing ghosts from hydrophone signals in a
streamer towed underwater close to the sea surface. A multi-axis
micro-electro-mechanical-system (MEMS) accelerometer with attitude
sensing is used to reduce the frequency spectral notch in the response of
the combined hydrophone-accelerometer system and to reduce the
sensitivity to ghost-producing downward traveling acoustic waves that are
sea-surface reflections of the primary upward traveling acoustic waves.
Multi-axis spring load cells provide high compliance and mechanical
isolation between stress members and the accelerometer system. The load
cells also provide signals representing the vibration of the stress
members. The signals can be used with an adaptive filter estimating the
mechanical transfer function between the vibration and the motion of the
accelerometer system to remove the vibration-induced noise from the
accelerometer signals.