Change detection methods for measuring deformation of the LNG storage tank's exterior wall cannot meet the requirements for extensive and comprehensive deformation analysis. The method proposed in this paper uses multi-source spatial data to detect the deformation of the LNG storage tank's exterior wall. Exterior wall data collected simultaneously by terrestrial and airborne laser scanners, as well as close-range and oblique photogrammetry, are pre-processed separately and then registered to the global point clouds. The deformation state of exterior wall is represented by a thorough assessment approach that takes into account four change indices. The results suggest that the registration precision of global point clouds is 6 mm. The global ovality of the LNG storage tank is 0.053%, with a tilt change of 2.58° and a deviation of 27 mm in the direction of the azimuth of 321.98°, an average value of 0.07 mm for depression and protrusion deformation, and a surface flatness of 21.3 mm. In this case, the flatness is greater than the variation threshold of the standard specification, indicating that the tank may have structural uneven settlement or other deformation problems. The attraction of the proposed method resides in its capacity to efficiently and accurately obtain spatial positioning and color information of the LNG storage tank's exterior wall, thereby providing a robust foundation for precise judgments regarding the deformation state.

中文翻译：

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多源空间数据支持的LNG储罐外壁3D变化检测方法

测量LNG储罐外壁变形的变化检测方法无法满足广泛、全面的变形分析的要求。本文提出的方法利用多源空间数据来检测LNG储罐外壁的变形。地面和机载激光扫描仪以及近距离和倾斜摄影测量同时收集的外墙数据分别进行预处理，然后注册到全局点云中。外墙的变形状态通过考虑四个变化指标的全面评估方法来表示。结果表明，全局点云的配准精度为6 mm。 LNG储罐整体椭圆度为0.053%，在方位角321.98°方向上倾斜变化为2.58°，偏差为27 mm，凹凸变形平均值为0.07 mm，表面平面度21.3毫米。在这种情况下，平整度大于标准规范的变化阈值，表明储罐可能存在结构不均匀沉降或其他变形问题。该方法的吸引力在于其能够高效、准确地获取LNG储罐外壁的空间定位和颜色信息，从而为精确判断变形状态提供坚实的基础。