Real Three-dimensional Modeling Technology Based On Oblique Photogrammetry

"Smart City" can not only accurately describe the spatial location of various types of construction information in the city,but also store and update the real-time change information of the city.Compared with traditional urban management methods,it is more conducive to urban planning,management,restructuring,and information inquiry.get on.The urban real-life 3D model is the basic data for constructing a "smart city".The model truly reproduces the spatial layout of urban features,and simply and intuitively describes the relative relationship between features,which is indispensable for the development of "smart cities".portion.This paper studies the urban real-world 3D modeling technology based on tilt photogrammetry technology,which provides a solid foundation for building a "smart city".The main research contents include:1)Analyzed the software and hardware system of the mainstream 3D modeling of tilting photogrammetry on the market,studied the principle of tilt photogrammetry technology and the characteristics of tilted photo,and combined the adjustment and intensive in the modeling of tilt photogrammetry.In-depth analysis of key technologies such as matching provides a theoretical basis for removing noise and repairing holes.2)Two types of noise generated by image intensive matching:(1)points away from the subject point cloud(flying point);(2)points(normal noise)mixed in the subject point cloud.The removal algorithm is designed according to the characteristics of each type of noise:(1)using the method based on statistical analysis and filtering to eliminate the flying point;(2)using the discrete roughness estimation method at the vertex V of the point cloud to eliminate the general noise..3)For the characteristics of tilt photography,the data is missing due to occlusion,and the data obtained by the vehicle mobile measurement system is used for cavity filling.For the missing part after the filling is completed,the shrinkage boundary is used for repair:the shrink ring is determined according to the shrinking direction and the shrinking distance,and the triangular patch is added based on the rule,and iteratively continues until the requirements are met.4)Taking the Shijingshan Yinhe Business District in Beijing as an example,the KWT-X6L multi-rotor UAV is equipped with ARC524 camera for data acquisition,and the generated point cloud data is denoised and repaired to establish a 3D real-time data model.Finally,GPS-RTK is used.On-site measurement,geometric accuracy evaluation of the model,verified the feasibility of tilt photogrammetry technology for high-precision urban 3D real-time modeling.