Real-time offshore coastal acoustic tomography (CAT) with mirror-transpond functionality is the most recent feature added to CAT to transfer travel-time data obtained in an offshore subsurface station to a shore station in real time, forming a round-trip travel time by original transmission and subsequent mirror transmission. The minimum unit, composed of one land and one offshore system, was operated to validate the performance of CAT with mirror-transpond functionality (MCAT) in the feasibility experiment, which was carried out in April 2017 in the Nekoseto Strait of the Seto Inland Sea, Japan. The root-mean-square error (RMSE) of the hourly mean range-average currents calculated from the original–original and original–mirror reciprocal travel-time pairs was 0.05 ms–1, significantly smaller than the variation range of the semidiurnal tidal current (0.2–0.3 ms–1) dominant at the experimental site. The RMSE for the residual current was also significantly smaller than its variation range. This study suggests the feasibility of using a compact MCAT array composed of one land and three offshore stations.

中文翻译：

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具有镜像转发功能的实时近海海岸声学断层扫描

具有镜像转发功能的实时近海海岸声层析成像 (CAT) 是添加到 CAT 的最新功能，用于将在近海地下站获得的旅行时间数据实时传输到岸站，形成往返旅行时间通过原始传输和随后的镜像传输。2017 年 4 月在濑户内海的猫濑户海峡进行的可行性试验中，运行了由 1 个陆地和 1 个海上系统组成的最小单元，以验证具有镜像转发功能 (MCAT) 的 CAT 的性能， 日本。从原始-原始和原始-镜像倒易走时对计算的每小时平均距离平均电流的均方根误差 (RMSE) 为 0.05 ms–1，显着小于试验场主导的半昼夜潮汐流（0.2-0.3 ms-1）的变化范围。剩余电流的均方根误差也明显小于其变化范围。这项研究表明了使用由一个陆地和三个海上站组成的紧凑型 MCAT 阵列的可行性。