Rotation processing technology for “Haimai” type ocean bottom node data

When underwater nodes are deployed in complex seabed terrain, their attitude angle changes can cause systematic distortion of the data collected by vertical and horizontal component detectors, making it difficult for seismic data to accurately reflect underground geological features. To address this issue, based on the "Haimai" node, a three-axis Cartesian coordinate system is uniformly defined for the node, dip azimuth sensor, and vertical three component detector. Based on the SEG criterion, the polarity output of the three component detector signal is adjusted, and the sequential rotation rule of the three components of the node is formulated, and the rotation matrix formula is derived. The verification of actual data at sea shows that the data rotation technique proposed in this paper can eliminate data anomalies caused by differences in the attitude of "Haimai" nodes, and the collected data can more accurately reflect underground geological information.