*5.1. Equipment for Monitoring Dynamic Responses*

MIMU used in the dynamic responses monitoring trial were from Mti300 inertial sensors by Xsens Technologies B.V. of the Netherlands (as shown in the upper right corner of Figure 14b). The specifications of Mti300 are given in Table 2. Furthermore, to demonstrate the accuracy and reliability of dynamic displacement responses by MIMU, a GPS monitoring system independently developed by BUCEA was installed on CB4A offshore oil platform. GPS RTK technology was used in this trial. The specifications of GPS are given in Table 3. The layout of the monitoring systems and the monitoring point for dynamic responses are indicated in Figure 14. Two sets of equipment were positioned at the northwest corner of the platform roof and attached to the roof railing by a sheet iron. The connecting line between the centers of MIMU and GPS antenna was directed toward the north–south. The MIMU was placed 20 cm to the north of the GPS antenna navigated by the NED coordinate system, and its X-axis was installed to the north.

**Figure 14.** Instrument setup for monitoring systems of dynamic responses of offshore oil platforms: (**a**) the layout of monitoring systems; (**b**) the monitoring point of dynamic responses.

**Table 2.** Performance index for Mti300.


**Table 3.** Performance index for GPS.

