基于无人机影像序列的城市精细化三维模型精度评估

为满足数字城市对精细化实景三维模型日益显著的需求,解决传统方法建模效率低的问题,提出一种基于无人机影像序列的城市精细化三维模型构建方法,通过现场25架次的航拍试验,构建了20个300 m×300 m测区范围的精细化模型和1个图书馆建筑精细化模型;利用检查点评估了全部精细化模型的精度,重点讨论了5种航拍高度和4种控制点选取方案对精细化模型精度的影响.分析结果表明:随着航拍高度降低、控制点数量增加,构建的精细化模型误差减小、精度得到提高;测区范围精细化三维模型最高精度达到平面±3.4cm、高程±3.1 cm,图书馆单体建筑精细化模型精度达到平面±3.4 cm、高程±1.5 cm;基于无人机序列影像的三维模型构建方法能够满足城市实景模型构建的精度要求,具有重要工程实用价值.

Method Accuracy Evaluations of Building Urban Detailed 3D Model Based on the Unmanned Aerial Vehicle Image Sequences and Its Accuracy Evaluatios

In order to satisfy the increasingly significant demand of the digital city for the detailed 3D model and solve the low efficiency problem of traditional modeling method, this paper summarizes a method of building the urban detailed model based on unmanned aerial vehicle (UAV) image sequences. Through the in-situ aerial photography test with 25 sorties, detailed models for 20 experiment area (300 m×300 m) and a library building were built. The accuracy of all detailed models were evaluated by field check points. The effect of 5 different flight heights and 4 different control points on the accuracy of the detailed models were discussed. The results show that the errors of the detailed models can be effectively decreased and the accuracy is improved by declining the flight height or increasing the number of control point. The highest accuracy of detailed models is ±3.4 cm in the plane and ±3.1 cm in the height, respectively. The accuracy of the detailed model for the library building is ±3.4 cm and ±1.5 cm, respectively. The method of building the urban detailed model using UAV image sequences can satisfy the accuracy requirement of the urban real scene model, which has great practical values in practical engineering.