Cross-section extraction and model reconstruction of lava tube based on L1-medial skeleton

• Published in: International journal of applied earth observation and geoinformation 2024-08, Vol.132, p.104062, Article 104062
• Main Authors: Yang, Qiao, Kang, Zhizhong, Hu, Teng, Cao, Zhen, Ye, Chenming, Liu, Dongming, Hu, Haoxiang, Shao, Shuai
• Format: Article
• Language: English
• Subjects: Lava tube; Lava tube cross-section extraction; Lava tube geometric modeling; Lava tube segmentation; Underground tunnel reconstruction
• ISSN: 1569-8432
• DOI: 10.1016/j.jag.2024.104062

•This method can accurately extract the central axis of complex lava tube structure, providing data support for us to understand the growth trend of lava tube more clearly.•This method has achieved automated parameter extraction for closed sections of lava tubes.•This method can construct lava tube models with high accuracy and reasonably supplement the missing point clouds of lava tubes caused by rockfall. At the same time, it provides various models of different LoD levels according to the demand, laying a foundation for subsequent model-based applications and monitoring.•This method provides innovative tools for parameter extraction and modeling of irregular tunnel structures, and has important application value and broad exploration space for in-depth study of geological phenomena such as lava tubes. Lunar lava tube caves, due to their unique geographical structure and potential as shelters, have repeatedly emerged as prime candidates or priority areas during discussions on lunar base site selection. However, owing to current technological limitations and the complexities of lunar exploration, obtaining detailed data directly from the interiors of lunar lava tubes poses a significant challenge. Hence, the study of terrestrial lava tubes assumes critical importance. By delving into Earth’s lava tubes, we can gain insights into crucial aspects such as their formation mechanisms, geological characteristics, and stability, which can then inform and guide research on lava tubes found on extraterrestrial bodies like the Moon and Mars. During the data acquisition process for lava tubes, given their intricate spatial configurations and dim lighting conditions, we have opted to employ LiDAR technology to collect point cloud data, revealing the internal structural information of the lava tubes. Consequently, this paper thoroughly explores a method for extracting lava tube parameters and constructing models using this point cloud data. This approach encompasses four key steps: data preprocessing, axis construction of the lava tube, cross-sectional feature extraction, and 3D model reconstruction. Initially, raw data is refined through the creation of point cloud voxels to mitigate noise interference. Subsequently, an iterative algorithm is utilized to obtain the L1-medial skeleton, enabling precise capture of the lava tube’s axis information. Using this extracted axis, we proceed with sampling at fixed intervals to derive cross-sectional points of the lava tube. T