2018 年 39 巻 3 号 p. 215-225
In marine seismic surveys to explore seafloor resources, the structure below the seafloor is estimated from the obtained sound waves, which are emitted by a marine seismic sound source and reflected or refracted between the layers below the seafloor. In order to estimate the structure below the seafloor from returned waves, information of the sound source position and the sound speed are needed. Marine seismic vibrators, which are one of the marine seismic sound sources, have some advantages such as high controllability of the frequency and phase of the sound, and oscillation at a high depth. However, when the sound source position is far from the sea surface, it becomes difficult to specify the exact position. In this paper, we propose a method to estimate the position of a marine seismic vibrator and the sound speed from obtained seismic data by formulating an optimization problem via hyperbolic Radon transform. Numerical simulations confirmed that the proposed method almost achieves theoretical lower bounds for the variances of the estimations.
