绘制芬兰的海底

作者：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。

Nautical charts are essential tools for marine navigation,Meritaito Ltd是一家领先的芬兰海洋调查服务和基础设施管理公司，生产官方的航海图表，用于芬兰水域的安全导航。该公司在全面的服务中拥有数十年的经验：

1. 维护水道
2. Use and maintenance of canals
3. Hydrographic surveying services
4. Hydraulic engineering
5. 水道设计和制造导航
6. Oil spill response services.

Meritaito成立于2010年，当时芬兰海事管理局，芬兰铁路管理局和芬兰道路管理局的水道合并为芬兰运输局（FTA）。FTA是在运输和通信部权力下运营的政府机构；它的主要责任是政府监督运输系统的维护和发展。

Organising the mission

深度以多种方式测量。从历史上看，使用了声音线。在现代，回声响起和激光雷达用于测量公海的海床。FTA过去曾在芬兰测试过测得的激光雷达，但成功却相当差。2015年，Meritaito按照FTA的要求组织了一项试点计划，这次使用了新技术，包括Leica Chiroptera II, a coastal survey LiDAR sensor. The results of the pilot program were satisfactory, and FTA requested two more hydrographic surveys, these took place in 2016 and 2017.

The data obtained from the surveys was used to制作最新的大规模航海图。Three different technologies were used for the data acquisition:

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

这些调查是guide for Meritaito for managing hydrographic surveys and improving the execution of a project containing bathymetric information from different data collection methods。

获得知识

For the first survey, Meritaito used different bathymetric sensors – among them was the Chiroptera II. The LiDAR data was requested separately, and, consequently, the surveys took place in different times.

“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”said Aaro Nurmiainen, Meritaito LiDAR expert.

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。

“激光雷达技术为其他应用开辟了道路。”said Nurmiainen.“Considering the long coastline and big number of lakes in Finland, this isthe ideal tool for shallow water surveys。”

领导丰富的经验

In the second project, FTA excluded all other methods and only kept LiDAR data for the shallow water areas. Meritaito used multi beam echosounders for the deeper parts.

“The Chiroptera II sensor allowed for rapid and accurate mapping, replacing the far less efficient single-beam mapping tool,”努尔米亚宁解释说。

Meritaito使用Leica Lidar调查工作室（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。

“The Chiroptera II captured the full waveform in both the 35 kHz bathymetric channel and the 500 kHz topographic channel and gave us seamless coastal and land surveying results,”努尔米亚宁解释说。“The results after the data processing in the second survey were not comparable with any other method previously used.”