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10 st / March 2016 www.sea-technology.com underwater structural monitoring market in the last few years. The safety and ex- tension of the operational life of structures is becoming the highest priority for com- panies. The core point of the monitoring tasks is understanding the problem be- fore it becomes unsolvable or the dam- age costs become multiple times more than if the structure were refurbished on time. Using the K-Observer system with the Kongsberg DAS sonar makes a com- plete 3D underwater scanning solution for scour and structural monitoring. Starting from the beginning of Febru- ary 2015, Kongsberg Maritime Subsea Monitoring, together with Hamburg Port Authority (HPA), has been conducting a long-term pilot project installation of the K-Observer system. The system is being used mainly for scour and structural mon- itoring applications around the port area. The DAS sonar is deployed with a pole and fxed on a dolphin, with the transduc- er pointing down to the area of interest. Taking into account the tide difference in the Port of Hamburg, which is approximately 3.6 m, the deployment procedure was performed during the lowest tide. It was im- portant to place the sonar as deep as possible, because the sonar must be completely submerged in order to perform the survey at any time. For the sake of avoiding any welding, the DAS sonar was deployed using a pole, which was fxed with straps around the dolphin. The reason for using this de- ployment method was to test for possible similar conditions in case the system is installed on offshore wind turbines, where in most cases welding is forbidden. Finally, the Sensor Interface Unit (SIU) was secured on the closest pontoon, which is easily accessible in case any support is needed or specifc tests need to be conducted. The system was confgured to monitor possible scour de- velopment around the area in front of the dolphin two times a day. For testing purposes, two different confgurations for the rotators in the DAS sonar were used. The frst confg- uration was set with the fnest rotation step size possible, 0.225°, and the second confguration was set to the more coarse rotation step size of 0.45°. Both setups have been K ongsberg's K-Observer is a fully autonomous monitoring, analysis and reporting system, supporting the integration of any underwater sensor for continuous and long-term sub- sea monitoring applications. Designed for operations near to the surface, the system fuses all sensor data to fulfll new customer requirements, while maintaining a cost-effcient operation by providing intelligent system control and ad- vanced data processing capabilities. The modularity and scalability of the system allows enhanced focus on specif- ic projects and applications for which the system can be used. The system features easy adaptation to different moni- toring tasks, ranging from small to complex 3D structural and scour monitoring systems around subsea structures and more near-to-surface monitoring applications, such as displacement of sediments, obstacle and debris detection, environmental monitoring, early leak detection and aqua- culture. Scour Monitoring at Port of Hamburg The scour monitoring application of the K-Observer sys- tem has been opening a completely new door in the 3D Advances in Long-Term Subsea Monitoring K-Observer, K-IMS Offer Permanent Port Monitoring By Pavel Kapricheski • Hans Ellingsen DAS sonar deployment at the Port of Hamburg.