倾斜摄影仿地飞行技术在山地大比例尺地形图测绘中的应用研究

Research on application of tilting photography in mountain scale topographic map mapping

针对在山区采用固定高度航摄得到的影像分辨率不一致、重叠度差异大、生产的地形图精度难以满足项目要求的问题,深入分析倾斜摄影和仿地飞行技术,提出采用倾斜摄影和仿地飞行相结合的方案进行山区大比例尺地形图的生成。首先,采用固定航高,搭载单镜头相机进行航空摄影作业,得到高精度数字地表模型(DSM);其次,基于DSM成果,搭载5镜头相机,采用仿地航线进行倾斜影像采集;然后,利用瞰景Smart3D软件生产实景三维模型,采用EPS软件进行大比例尺地形图测绘;最后,采用实地采集的特征点,在EPS软件中对地形图精度进行检测。由检测结果可知:采用该方案生成的地形图其平面位置中误差可达到±0.231 m,高程中误差可达到±0.264 m,满足1:500地形图精度要求,可为山区大比例尺地形图的生产提供借鉴。

Aiming at the problems of inconsistent resolution and large overlap difference of images obtained by aerial photography with fixed height in mountainous areas,the accuracy of topographic map produced is difficult to meet the project requirements.After an in-depth analysis of tilt photography and ground imitation flight technology,this paper proposes combining tilt photography and ground imitation flight to produce large-scale topographic map in mountainous areas.Firstly,the high-precision digital surface model(DSM)is obtained by using fixed altitude and single-lens cameras for aerial photography.Secondly,based on the results of DSM,a 5-lens camera was installed to collect oblique images by mimicking the route.Then,the eye-view Smart3D software was used to produce the real 3D model,and the EPS software was used for large-scale topographic map mapping.Finally,feature points collected on the spot are used to detect the topographic map accuracy in EPS software.It can be seen from the test results that the topographic map produced by this scheme can reach±0.231 m in-plane position and±0.264 m in elevation,which meets the accuracy requirements of 1:500 topographic map and can bring references for the production of large-scale topographic maps in mountainous areas.