Quality Evaluation of Digital Twins Generated Based on UAV Photogrammetry and TLS: Bridge Case Study

比较由无人机摄影测量和地面激光扫描（TLS）构建的澳大利亚一座 1893 年历史木桁架桥的点云“数字孪生”。通过平面和圆柱拟合、点云间距离、剖面、点密度和比例误差评估质量。无人机点云在许多指标上达到了毫米级的一致性，但点密度约为 TLS 的一半，且存在厘米级的比例误差。

主要发现

• About 349 million UAV points versus over 1,590 million TLS points
• Plane fitting RMSE about 1.96 mm (UAV); cylinder fitting STD/RMSE above 4 mm (UAV) vs below 3.4 mm (TLS)
• Cloud-to-cloud mean differences under 4.5 mm for piers and under 8.5 mm for another part
• UAV scale error at centimetre level versus millimetre level for TLS; TLS density roughly double

局限

• Single bridge, only a middle section analysed
• TLS treated as ground truth
• UAV GNSS can degrade under the bridge
• Effects of survey planning and processing settings left for future work