Abstract: Traditional surveying and mapping products can only provide abstract plane geometry information for water conservancy project construction,lacking authenticity and three-dimensional texture information. In order to reflect and express the construction of water conservancy projects in a real,3D and sequential way,this paper takes a water conservancy project as an example,by using Feima multirotor UAV D2000 and DOP3000 tilt photography module,the real-time dynamic differential POS based on carrier phase and post-processing dynamic differential POS image free 3D modeling of tilt photography reality for water conservancy projects is carried out. The precision comparison results of the final models show that the plane accuracy of the imageless 3D models based on the network RTK and PPK POS is equivalent,while the elevation accuracy of the model based on PPK POS is better than that of the network RTK POS. However,both models can meet the requirements of 3D model products with 1∶500 mapping scale,and both models have rich texture information,which can be used to assist the geological exploration of hydraulic engineering,safety monitoring and intelligent water conservancy construction.

Key words: tilt photogrammetry, UAV, 3D real scene modeling, water conservancy projects