Mapping Finland’s ocean floor

Author:Penny Boviatsou

准确的航海图表可确保安全导航和更好的航行计划。这些是海上地区和沿海地区的图形表示，显示了水的深度和土地高度，海床和海岸线的细节，导航威胁以及港口等结构。

航海图是海洋导航的重要工具，Meritaito Ltd, a leading Finnish marine survey service and infrastructure management company, produces official nautical charts for safe navigation in Finnish waters. The company has decades of experience in a comprehensive range of services in:

1. 维护水道
2. 使用和维护的canals
3. Hydrographic surveying services
4. Hydraulic engineering
5. Waterways design and manufacturing of aids to navigation
6. 漏油响应服务。

Meritaito was founded in 2010 when the waterways functions of the Finnish Maritime Administration, the Finnish Rail Administration and the Finnish Road Administration merged into the Finnish Transport Agency (FTA). The FTA is a government agency operating under the authority of the Ministry of Transport and Communications; its main responsibility is the maintenance and development of the transport system overseen by the government.

组织任务

Depths are measured in a variety of ways. Historically, the sounding line was used. In modern times, echo sounding, and LiDAR are used for measuring the seabed in the open sea. The FTA had tested bathymetric LiDAR in Finland in the past but with rather poor success. In 2015, Meritaito organised a pilot program after FTA’s request, and this time new technology was used including theLeica Chiroptera II，沿海调查激光传感器。试点计划的结果令人满意，FTA要求另外两项水文调查，这些调查发生在2016年和2017年。

The data obtained from the surveys was used toproduce up-to-date, large-scale nautical charts。Three different technologies were used for the data acquisition:

1. 单梁回声（SBE）
2. Multibeam echosounding (MBES)
3. 测深痛。

These surveys worked as aMeritaito的指南管理水文调查并改善了来自不同数据收集方法的测深信息的项目的执行。

获得知识

在第一次调查中，Meritaito使用了不同的测深传感器 - 其中包括Chiroptera II。分别请求激光雷达数据，因此，调查是在不同时间进行的。

“对于浅层区域，我们使用了单光束回声器和Leica Chiroptera II，对于更深的区域，多层回声器”Meritaito LiDar专家Aaro Nurmiainen说。

完成数据评估后，Meritaito为FTA创建了报告。在对报告分析之后，FTA得出结论认为，Chiroptera II沿海调查LIDAR技术可用于替代沿海地区的单束回声器。

“The LiDAR technology opened the way for other applications,”努尔米亚宁说。“考虑到芬兰的长海岸线和大量湖泊，这是the ideal tool for shallow water surveys。”

领导丰富的经验

在第二个项目中，FTA排除了所有其他方法，并且仅保留了浅水区的激光雷达数据。Meritaito将多光束回声器用于更深的部分。

“The Chiroptera II sensor allowed for rapid and accurate mapping, replacing the far less efficient single-beam mapping tool,”explained Nurmiainen.

Meritaito使用了Leica LiDAR Survey Studio（Leica LSS）和Terrasolid Software Suite，以创建快速自动化的工作流程。处理和评估后，FTA收到了最终产品，准备了该机构的映射项目。

“ Chiroptera II捕获了35 kHz的测深通道和500 kHz地形通道中的完整波形，并给了我们无缝的沿海和土地测量结果，”explained Nurmiainen.“第二次调查中的数据处理后的结果与先前使用的任何其他方法都无法比拟。”