Computing and Retrieving 3D Archaeological Structures from Subsurface Surveying

今天的考古发掘是缓慢的，保护的成本很容易超过挖掘的成本。 该项目正在研究和开发从地面穿透雷达、磁力测量和电导率传感器获得的地下非侵入性测量中恢复三维地下结构的方法。结果不仅为进一步的挖掘提供了线索，而且还提供了可以研究的3D模型，就像它们已经被挖掘出来一样。 研究的三个基本挑战是恢复体积材料分布的逆问题，地下体积的分割，以及包括感兴趣的结构的表面的重建。在地下体积的恢复中，以其原始偏微分方程形式引入高保真的地球物理模型。同时求解来自多个模态的偏微分方程以产生材料分布体积。 在分割中，用于估计图切割的图谱方法发现地下体素的集群，其在分区内具有紧密连接，而在分区之间具有松散连接。基于多尺度图切割的方法显著地加速了该过程，而归一化切割的分组属性有助于将相同材料的多个片段聚类在一起。 在表面重建中，从分割或从目标材料搜索获得的边界从无组织的体素云转换为连接的表面。一个自下而上的方法，介绍了小组的邻居到小平面的重叠量指导三角测量过程。 考古学PI提供了关于预期发现哪些结构的先验知识，这些结构可以引导分割和重建步骤。地球科学和考古学PI领导了玻利维亚蒂瓦纳库遗址的数据采集工作。所有原始数据以及恢复的3D模型将向公众提供。

Today's archaeological excavations are slow and the cost for conservation can easily exceed the cost of excavation. This project is investigating and developing methods for the recovery of 3D underground structures from subsurface non-invasive measurements obtained with ground penetrating radar, magnetometry, and conductivity sensors. The results will not only provide hints for further excavation but also 3D models that can be studied as if they were already excavated. The three fundamental challenges investigated are the inverse problem of recovering the volumetric material distribution, the segmentation of the underground volumes, and the reconstruction of the surfaces that comprise interesting structures. In the recovery of the underground volume, high-fidelity geophysics models are introduced in their original partial differential equation form. Partial differential equations from multiple modalities are simultaneously solved to yield a material distribution volume. In segmentation, a graph spectral method for estimating graph cuts finds clusters of underground voxels with tight connections within partitions and loose connections between partitions. A method based on multi-scale graph cuts significantly accelerates the process while the grouping properties of the normalized cuts help in clustering together multiple fragments of the same material. In surface reconstruction, boundaries obtained from segmentation or from targeted material search are converted from unorganized voxel clouds to connected surfaces. A bottom-up approach is introduced that groups neighborhoods into facets whose amount of overlap guides the triangulation process. The archaeology PIs are providing prior knowledge on what structures are expected to be found which can lead the segmentation and the reconstruction steps.The geoscience and archaeology PIs lead the effort of data acquisition at the Tiwanaku site in Bolivia. All original data as well as recovered 3D models will be made available to the public.