Preserving Romania’s Speleological Heritage with Point Cloud and GNSS Data

作者：乔治·达米安（George Damian），雷纳塔·巴拉达斯（Renata Barradas）

3D laser scanning provides a high-resolution, non-invasive documentation method to understand natural and cultural sites and manage its exposure to natural and man-made threats. Researchers in diverse fields are unlocking numerous applications using this technology, just like speleologists who are using laser scan data to study and measure caves with millimetre-level accuracy in a non-intrusive way. Point cloud data allows experts to extract cartographic information and calculate areas and volumes to study the evolution of topographic and bathymetric features in caves.

为了保存和了解罗马尼亚的杂种遗产，顶级地理, the Leica Geosystems’ dealer in Romania, laser scanned the Meziad Cave, a 6,298-metre natural wonder in the western Carpathians. The Meziad Cave, the first cave adapted for tourism in Romania, is known for its spectacular subterranean landscapes with beautiful speleothems (stalactites, stalagmites, columns and curtains). The cave is also home to one of the largest colony of bats in South-East Europe and microscopic endemic organisms (some of them confined to the Meziad Cave).

这项高分辨率3D文档旨在准确捕获该地点的复杂性，并引入积极的保护措施，以维护或恢复现场，然后进行任何考古学和古生物学侵入性研究，以修改原始地点。此外，顶级Geocart创建了3D模型和其他可交付成果，以使其客户Spelemat能够存储，组织和检索信息以进行进一步分析。数据提供了文件并记录了这种自然和文化遗产的原位状态。

A mission inside the cave

顶级Geocart与Spelemat的专家一起设计了该项目，并计划在地球内部进行此任务。理解，尊重和促进技术和地理空间数据的使用的这组专家，他们收集了现场数据，而不会影响环境。除了使用非侵入/非侵入性技术外，该团队还必须考虑正确的时机才能进入洞穴，因为天气和洞穴的河流流是成功完成此任务的关键因素。

顶级Geocart的专家使用了一流的软件和硬件，包括：

• Leica RTC360 3D激光扫描仪
• Leica BLK360成像激光扫描仪
• Leica Viva GS16 GNSS智能天线
• Leica GS18 T RTK GNSS Rover
• Leica Disto™S910

对于点云对齐，建模和GNSS网络团队依赖：

• Leica Infinity软件
• Leica Cyclone寄存器3603D laser scanning point cloud registration software
• Leica Cyclone模型
• Leica Cyclone 3dr
• Leica GNSS Spider software

该团队通过GNSS Spider Software运行的罗马尼亚国家参考站网络（ROMPOS）的实时更正，通过GS16和GS18 T GNSS RTK ROVERS进行了搜寻，并通过GS16和GS18 T GNSS RTK Rovers进行了地理参考。需要智能链接校正，因为山坡和树木的山区环境阻碍了该区域，并且不时丢失了GSM/GPRS信号。GS16和GS18 T使用SmartLink服务的能力是涵盖这些空白的关键，并且始终具有精确的位置。为了提供最准确的职位，该团队还依靠两位RTK流浪者的Leica RTKPLUS技术，因为它通过选择最佳GNSS信号来智能适应不断变化的条件。

在洞穴的内部，团队带着特殊的衣服和配件穿过河水，以安全地运输设备。在防水容器和漂浮袋的内部，RTC360和BLK360从位置漂移到位置。速度和精度是原始的，同时在10°C度以下的温度下，在胸部上方的水位上扫描。

Geared with the RTC360, the team captured the larger parts of the cave and artefacts, creating coloured 3D point clouds in under two minutes. With a scanning speed of up to 2 million points per second, advanced HDR imaging system and automated target-less field registration in the RTC360, Top Geocart captured the sites of interest inside the cave in two hours at 750 meters per hour.

At the push of a button, Top Geocart captured full-colour panoramic images overlaid on a high-accuracy point cloud for the narrow parts of the cave with the smallest and lightest imaging laser scanner - the BLK360. For those areas where it was not possible to set on a tripod the laser scanners, measurements were made with the DISTO™ 910.

任务的可交付成果

在靠近条目的洞穴之外，团队使用Leica Geosystems提供的Exchange Service自动并无缝将数据从站点转移到办公室，从而减少了在荒凉环境中的时间。通过Leica Exchange轻松在现场和办公室之间传输数据，使专家可以使用Leica Disto™Transfer和Leica Disto™Plan应用程序对数据进行首次检查。使用Leica Cyclone Field 360顶部的地理器在洞穴入口自动预注册和对齐扫描。

回到办公室，BLK360和RTC360的点云数据已在Cyclone寄存器360中注册。GNSS数据被检查并使用Infinity软件处理，在GNSS项目中也导入了Disto™数据。与Spelemat一起，Top Geocart创建了一个统一的点云，作为Cyclone寄存器360项目，并以E57和LGS格式导出，以使用Jetstream观看器，一种轻重点云查看工具。E57文件是在Leica Cyclone 3DR中导入的，以从点云中创建网格和计算数字地形模型（DTM）。

专家们还创建了2D地形地图和3D DTM，其中包含来自GS16和GS18 T RTK Rovers的数据，以为访问者开发新的曲目和路径。从Disto™S910收集的数据中提取了带有3D点和图片的距离和CAD文件。

The data provided will support researchers, tourists and facility managers alike. It will guide feasibility studies for touristic plans and be used as marketing material to invite visitors to explore this natural wonder. Point cloud deliverables provide researchers with a digital twin of the cave where they can extract any profile and 3D measurement. At the same time, GNSS data helped to identify the areas and paths to create access for tourists and scientists.

“徕卡呈规则和顶级Geocart提供完整software and hardware set for the entire workflow. The sensors have the capabilities to work in difficult environments and meet the highest standards in measurement excellence. The management and specialists fromSpelemat承认他们能够比以往任何时候Spelemat的洞穴管理专家Viorel Lascu说。

捕获Meziad Cave的成功说服了Spelemat投资RTC360，BLK360，Disto™，以继续探索和理解罗马尼亚的自然奇观。