NEC Corp headquarters in Tokyo
06:00 JST, July 17, 2024
NEC Corp. has developed a new system to measure tide levels with high accuracy using laser beams and buoys on the ocean surface. The company aims to put the system into practice in fiscal 2025, with the expectation that it will be used by central and local governments.
During the earthquake in the Noto Peninsula in January, the ground shifted so much that the seabed rose above the ocean surface, making measurements impossible over a long period of time. With that experience in mind, NEC began work on its new system.
Conventional methods of measuring tide levels use radio waves. The waves are directed from above to the sea surface and the time it takes for them to bounce back is calculated. To measure tide levels using this method, equipment must be attached to the shore. Therefore, when ground movements shift the equipment, it becomes difficult to measure the tide accurately. The recovery process also takes a long time.
The new system, however, emits infrared laser beams from a device on a distant piece of land to measure the distance between buoys floating on the sea surface tens or hundreds of meters away and nearby dikes and structures. The system measures the tide level by comparing changes in the positions of the buoys and structures. The system is less sensitive to the effects of ground motion and is expected to be more accurate.
