Intensity Data Correction for Long-Range Terrestrial Laser Scanners: A Case Study of Target Differentiation in an Intertidal Zone
Intensity Data Correction for Long-Range Terrestrial Laser Scanners: A Case Study of Target Differentiation in an Intertidal Zone
复制标题
DOI：
10.3390/rs11030331
复制
发表时间：
2019-02
期刊：
影响因子：
--
通讯作者：
K. Tan;Jin Chen;Weiwei Qian;Weiguo Zhang;Fang Shen;Xiaojun Cheng
中科院分区：
文献类型：
--
作者：
K. Tan;Jin Chen;Weiwei Qian;Weiguo Zhang;Fang Shen;Xiaojun Cheng
地面激光扫描仪（TLS）记录的光强数据包含被扫描目标的光谱特征，主要受入射角和距离的影响。在这项研究中，提出了一种改进的可实现的方法来经验校正的强度数据的长距离TLS。与现有的方法类似，入射角-强度关系的估计使用一些参考目标在实验室中扫描。由于室内环境的长度限制和数据处理的繁琐性，距离-强度关系的推导是通过选择一些距离覆盖所采用的长距离TLS的整个距离尺度的自然均匀目标来进行的。利用Riegl VZ-4000型长距离TLS的地震烈度数据，对上海崇明岛潮间带的地震烈度进行了校正和点云分类，验证了改进方法的可行性。结果表明，改进后的方法能准确消除远距离目标声强数据受入射角和距离的影响，研究海区目标声强数据的变异系数可降低约54%。对潮间带的分类结果表明，改进后的方法能有效消除同一目标原始强度数据中入射角和距离引起的变化，得到仅依赖于目标特征的修正强度，分类精度提高了49%。
The intensity data recorded by a terrestrial laser scanner (TLS) contain spectral characteristics of a scanned target and are mainly influenced by incidence angle and distance. In this study, an improved implementable method is proposed to empirically correct the intensity data of long-distance TLSs. Similar to existing methods, the incidence angle–intensity relationship is estimated using some reference targets scanned in the laboratory. By contrast, due to the length limit of indoor environments and the laborious data processing, the distance–intensity relationship is derived by selecting some natural homogeneous targets with distances covering the entire distance scale of the adopted long-distance TLS. A case study of intensity correction and point cloud classification in an intertidal zone in Chongming Island, Shanghai, China, is conducted to validate the feasibility of the improved method by using the intensity data of a long-distance TLS (Riegl VZ-4000). Results indicate that the improved method can accurately eliminate the effects of incidence angle and distance on the intensity data of long-distance TLSs; the coefficient of variation of the intensity data for the targets in the study intertidal zone can be reduced by approximately 54%. The classification results of the study intertidal zone show that the improved method can effectively eliminate the variations caused by the incidence angle and distance in the original intensity data of the same target to obtain a corrected intensity that merely depends on target characteristics for improving classification accuracy by 49%.