Integrated Ground–Air–Space Exploration Technology of Jingpo Lake Lava Tubes

Lava tubes play an important role in base construction and understanding planetary geological development on extraterrestrial bodies. However, our understanding of lava tube morphology on Earth as a reference for extraterrestrial bodies remains limited. Existing research mainly focuses on their formation mechanisms and uses a single approach to study their morphology. To fill this gap, we conducted a multi-platform investigation of a lava tube near Jingpo Lake, Heilongjiang Province, China, employing space-, air-, and ground-based techniques. The method presented in this paper can assist in the comprehensive exploration of lunar lava tubes in the future. First, data covering this large lava tube area were collected using synthetic aperture radar (SAR), due to its all-weather capability, from which distribution information on lava tube skylights was retrieved. Furthermore, close-range point cloud data of the lava tube skylight areas were collected from drones equipped with the DJI Zenmuse L1 LiDAR sensor, which allows for high-resolution data acquisition and the creation of detailed models, providing local high-precision point clouds. Additionally, Light Detection and Ranging (LiDAR) was used for detailed point cloud collection inside the lava tubes, and through the registration of high-precision point clouds of the skylights both inside and outside the tube, comprehensive point cloud data of the entire lava tube were obtained. Hyperspectral LiDAR was also used to collect data of the tube walls under dark conditions, addressing the issue of consistency matching between hyperspectral imaging and laser far-field spots, enabling integrated spatial-spectral data acquisition. Finally, ground-penetrating radar was also employed for subsurface structural analysis, benefiting from its high penetration capabilities to acquire more detailed information on the underground morphology of the lava tubes. Our experiments demonstrate that this multi-sensor approach provides comprehensive information on terrain, lava tube orientation, cave distribution, and the internal environment of the lava tube system.