Terrestrial LiDAR Scans in the CTFS-ForestGEO Plot at Harvard Forest 2021

In heavily forested and jungle environments where GPS reception is unavailable due to dense canopy cover, it is difficult to determine one's location. Currently, either visual landmarks are used, or open clearings are found where GPS reception can be reestablished. Alternatively, dead-reckoning systems that rely on Inertial Measurement Unit sensor suites can help over moderate distances, but these devices cannot retain positional accuracy over extended ranges. Creare proposes to address this problem by developing the Tree Positioning System. This technological solution will combine a metrology system for determining local tree maps, and geolocalization algorithms that perform spatial pattern matching of local tree maps against a georegistered reference tree map of the area. This system was tested by scanning trees in the ForestGEO plot at Harvard Forest in June 2021.在茂密森林与丛林环境中，由于浓密树冠的遮挡，全球定位系统（Global Positioning System, GPS）信号无法覆盖，人员难以确定自身位置。当前常用的定位方案要么借助视觉地标开展定位，要么寻找开阔空地以重新获取GPS信号。此外，依赖惯性测量单元（Inertial Measurement Unit）传感器套件的航位推算系统，可在中等距离范围内提供定位辅助，但此类设备无法在长距离作业中维持稳定的定位精度。Creare公司提出将开发树木定位系统（Tree Positioning System）以解决该问题。该技术方案将结合用于构建本地树木地图的测绘系统，以及将本地树木地图与该区域地理配准参考树木地图进行空间模式匹配的地理定位算法。该系统于2021年6月在哈佛大学森林（Harvard Forest）的ForestGEO样地中完成了树木扫描测试。