Calibration of Laser Scanners

激光扫描仪的校准

• 批准号: 518820245
• 负责人: Professor Dr.-Ing. Heiner Kuhlmann
• 金额: --
• 依托单位: Lehrstuhl für Geodäsie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/518820245?language=en
• 关键词: Calibration; Laser; Scanners

The accuracy of terrestrial laser scanners (TLS) is mitigated by internal scanner misalignments (calibration parameters) whose magnitude mostly exceeds the one of random deviations. This has mainly two consequences in the context of a deformation analysis: On the one hand, the differences d between the measurements at two epochs are biased by the systematic deviations. On the other hand, systematic deviations affect adjacent points in a similar way, which causes correlations between the measurements that need to be incorporated into the stochastic model Σ_dd. To guarantee an unbiased deformation analysis, the systematic deviations must be calibrated. Thus, the goal of this project as part of the whole research unit with the projects is to - reduce systematic deviations to get unbiased point cloud differences d - and to derive a fully populated variance-covariance matrix for the calibration parameters of the scanner Σ_cc, that is an essential part of Σ_dd. A further development of TLS calibration procedures is one of the linchpins for the unbiased laser scanner-based deformation analysis that aims at detecting small geometric changes. Namely, the calibration is of high relevance for several points raised in this proposal for a research unit: a) not-accounting for systematic deviations causing artifacts in data that can bias the surface representation; b) removing instrument-related systematic deviations increases the sensitivity; c) correct quantification of the calibration uncertainty is necessary for the comprehensive measurement uncertainty estimation; d) a correct functional model of systematic errors is necessary for unbiased planning of optimal instrument positioning.

地面激光扫描仪（TLS）的精度因内部扫描仪未对准（校准参数）而降低，其幅度大多超过随机偏差之一。这在变形分析中主要有两个后果：一方面，两个历元的测量值之间的差异 d 因系统偏差而产生偏差。另一方面，系统偏差以类似的方式影响相邻点，这导致需要将测量结果合并到随机模型 Σ_dd 中。为了保证变形分析的公正性，必须校准系统偏差。因此，作为整个研究单元项目的一部分，该项目的目标是 - 减少系统偏差以获得无偏点云差异 d - 并为扫描仪 Σ_cc 的校准参数导出完全填充的方差-协方差矩阵，这是 Σ_dd 的重要组成部分。 TLS 校准程序的进一步发展是基于激光扫描仪的无偏变形分析的关键之一，旨在检测微小的几何变化。也就是说，校准与本研究单位提案中提出的几点具有高度相关性：a）没有考虑系统偏差，这些偏差会导致数据中的伪影，从而使表面表示产生偏差； b) 消除与仪器相关的系统偏差可提高灵敏度； c) 校准不确定度的正确量化对于综合测量不确定度估计是必要的； d) 正确的系统误差功能模型对于无偏规划最佳仪器定位是必要的。