Creating a 3D map of the world’s largest volcanic cave to aid future space missions

尽管相距数十万公里，但兰萨罗特岛和月亮岛也有着显着的相似之处。西班牙岛属于大西洋的金丝雀群岛，是世界上最大的火山洞穴和类似于月球景观的风景。实际上，该岛被选为在太空任务之前的宇航员训练的位置。最近，兰萨罗特（Lanzarote）的电晕熔岩管帮助了欧洲航天局的团队探索和研究在月球和火星等行星上观察到的类似特征的洞穴。

由于最新的地理空间技术进步和创新，2017年由汤玛索·桑塔加塔（Tommaso Santagata）从虚拟地理位置机构领导维亚, deploying3D陆地激光扫描（TLS）和Mobile Mapping solutions, resulting in the first ever 3D replica of the largest lava tube on Earth.

探索电晕熔岩管的深度

电晕熔岩管位于兰萨罗特（Lanzarote）的北部，延伸了8.5公里，由干燥和淹没的通道组成，其中一些部分宽25米。尽管最初的探索和初始映射始于七十年代，但直到第一个地形调查进行了六十年代初，其真正的扩展才是未知的。由地方政府Cabildo de Lanzarote委托的最新，最雄心勃勃的3D扫描项目也实施了最新的移动地图技术，该技术是欧洲航天局培训课程Pangaea-X的一部分。这项培训使他们能够测试将在未来太空任务中使用的新工具和技术。

为了成功执行该项目，在一年的过程中完成了各种Leica GeoSystems解决方案，包括Leica HDS7000,Leica Scanstation P40和Leica BLK360激光扫描仪以及Leica Pegasus：背包mobile mapping solution. The result is the largest 3D replica of a lava tube on the planet with 5.7 kilometers of cave passages mapped.

使用最新的激光扫描技术捕获所有细节

Three individual surveys and over 440 scans were completed to map the lava tube system, composed of different sections connected to each other through external collapses. These collapses were used to geo-reference the laser scanning surveys performed inside the cave on the external surface. This was made possible with Global Navigation Satellite System (GNSS) measurements, Light Detection and Ranging (LiDAR) data from the Spanish Geological Service, and through photogrammetry data obtained with unmanned aerial vehicle (UAV) flights along the cave path.

More specifically, 800 metres of the above sea level passages were mapped using the HDS7000 and an estimated five kilometres using a ScanStation P40. In addition, the BLK360 imaging laser scanner was deployed to scan an upper level of around 300 metres during the PANGAEA-X expedition.

Leica Pegasus的准确性和机动性提高：背包

为了生成更详细的3D地图，使用Pegasus：背包移动映射解决方案进行了调查。旨在在地上和地下环境中捕获3D数据，其中图像和点云由五个摄像机和两个LiDAR PROFILER收集。它的轻量级和人体工程学结构使团队能够舒适地浏览困难的地形并立即可视化手持板计算机上的数据。

“由于熔岩管系统的复杂和地下性质，Pegasus：Backpack被部署以获取融合的SLAM数据 - 在带有GNSS数据的户外环境中开始和结束，但在很大程度上探索了没有卫星的洞穴，”Co-Founder of Virtual Geographic Agency Vigea 3D and an expert on Lanzarote’s volcanic cave system. As the lengthiest part of the mission was carried out without any GNSS information, the second phase of the data processing was to reinforce the calculation of the path recorded using a SLAM algorithm and the information obtained by the LiDAR mounted on the Pegasus:Backpack.

Processing the data and creating the final 3D map

“Having gathered large amounts of data — 400 GB corresponding to the raw laser scanning data alone — the狮子旋风然后部署了3D点云处理办公室软件以对齐扫描并处理洞穴的统一点云。” Santagata说。“一旦3D地图在单点云中可用，就会生成几个输出作为地形图，并带有熔岩管的计划和部分。”此外，随后将数据用于与地球上其他熔岩管进行比较，目的是在月球和火星上研究类似的特征 - 使用该操作Autodesk AutoCAD2017年软件。

除了对未来太空任务的科学目的和培训外，数据还用于生产多媒体和交互内容，例如视频动画，虚拟现实和桌面应用程序，显示了更广泛的公众是Corona熔岩管系统中鲜为人知的部分。只有有限的部分向Cueva de Los Verdes和Jameos del Agua开放。此外，该项目的结果是在Cabildo de Lanzarote在2019年组织的旅游洞穴管理期间提出的，该洞穴在2019年安装了一个虚拟现实立场，向公众展示了洞穴。

Latest expedition update: Supporting the search for “stone-eating” bacteria

In spring 2021, Santagata returned to Lanzarote to support a microbiology research project. The Tubolan project, led by Ana Miller, geomicrobiologist at the Institute of Natural Resources and Agrobiology of Seville (CSIC), was set up to study the microbial organisms living in the Lanzarote lava tube systems. The team’s findings will help those searching for life on the Moon and Mars, which also have lava systems. Although the conditions are different to those on earth, the Martian and lunar cave systems could theoretically also support chemolithoautotrophic microorganisms that survive and grow by using and transforming minerals. In the framework of the Tubolan project, Santagata used a Leica BLK360 to make scans and 360 degree videos – contributing to the study of caves’ formation and uncovering more of the caves’ geography than ever before. The amazing video footage taken can be watched onVIGEA’s YouTube channel.

进一步阅读：
Sauro F.，Pozzobon R.，Santagata T.，Tomasi I.，Tonello M.，Martínez-FríasJ。，Smets L.M.，GómezG.D。，Massironi M.（2019）兰萨罗特的火山洞：一种自然实验室，用于了解火山孔隙遗传学过程和行星洞穴。在Lanzarote和Chinijo群岛地质公园中：从地球到太空（第125-142页）。施普林格，康。

SAURO F, POZZOBON R。DE BERNARDINI MASSIRONI MS P., SANTAGATA T., DE WAELE J. (2020)地球，月亮和火星上的熔岩管：比较行星学揭示其大小和形态的评论. Earth Science Reviews 103288.