Investigation and optimization of OBC sensor array coupling to the seafloor

In order to improve sensor coupling in the offshore environment novel and systematic approaches are needed. Today several approaches exist for the vertical component of a three component sensor. But there are no systematic investigations for the horizonta l components. Most of the vertical approaches use special pre-processing methods like separation of upgoing and downgoing P and S wave-fields or inverse filtering. But to understand the sensor coupling to the seafloor it is essential to investigate the se nsor coupling itself. For a systematic investigation it is substantial to understand the connection of different sensor-housing designs to variable seafloors. Which design makes the sensor coupling better and why? What influence has the seafloor soil cond itions and how deep should an OBC be trenched and how strong is the cable-tension influence? Why is the sensor coupling different for all three components? All these questions will be investigated by using FEM/FED simulations (e.g. Matlab FEM-toolbox, Mul tiphysics) and doing tests in a water-tank. The water tank will be hanged to the floor to decouple the water-tank from the ambient noise. The most critical challenges will be to simulate the correct soil coupling with the sensor-housing for horizontal mo vements, because current models fits not into measurements (e.g. Duennebier et al., 1995) and can only be used as a start model. To find the optimal mechanical node design is also a critical challenge, because of to integrate the new design into the offsh ore installation procedures.