Summary

Corrections for source and receiver positioning and clock-drift errors are early steps in the processing of ocean bottom seismic (OBS) data. We have implemented an optimization process to correct jointly for these errors, while a water velocity model gets updated from an initial uniform estimate to a final time- and depth-dependent version at the node locations. The main novel parts in the process are using a non-linear clock-drift correction term, using a higher-order polynomial model for the vertical profile of water-velocity and an enhanced data pre-conditioning for optimization. A real data example confirms the success of the approach.