Research On 3D Reality Reconstruction Technology Based On Multi-sources Measurement Data Fusion

The use of oblique photography is a common and effective method for Unmanned Aerial Vehicle(UAV)aerial survey.The oblique photography can achieve multi-angle images acquisition which can ensure high efficiency and accuracy to geolocation and three-dimensional reconstruction.It has become the main technique of UAV aerial survey in the world,and gradually has been applied to geophysical exploration and other fields.Surveying and mapping technology is the foundation and key of land use planning.The traditional two-dimensional graphic design method with manual outdoor measurement is mainly used in land consolidation planning,which has heavy workload of field mapping by low efficiency and too much cost.The UAV aerial survey has become an effective way to solve the above problems.So researching for a 3D modeling system with UAV tilted photogrammetric technology will lay a solid foundation for the large scale commercial application of tilting photogrammetric technology.This dissertation focuses on the modeling technology of 3D reality with oblique photogrammetry,that makes a systematic research on several key problems including aerial triangulation of tilted image method,multi-view stereoscopic precise 3D modeling technology,the integrated data fusion method of aerial images and mobile measurement as well as the processing technology of the integration planning and design with both 2D and 3D data.A prototype of the system has been developed to carry out the UAV tilted photogrammetry test and vehicle images test.The main works include the following aspects:1?The 2D and 3D integrated planning model system,established by 3D data acquisition and processing method in this dissertation,reveals the characteristics of multi-view,multi-angle and large-angle of tilt image sequence.Through the experiment,several bottleneck problems,which the traditional image matching method can not solve,have been analyzed the influences on land consolidation planning and design.The conditions of 3D real scene reconstruction technology,based on multi-source measurement data fusion,are determined as follows:(1)Massive precise 3D data of large scenes,(2)Accurate texture data,(3)Control point data.2?The three-dimensional modeling method with the mapping level precision is studied in this dissertation.By combining the latest semi-global dense point cloud matching algorithm in computer vision field and throughout establishing the strict correspondence between images and models,the method forms the interactive iterative acquisition mode from 2D edge feature through front cross 3D vectors to projection to image 2D feature verification,which supported by multi-view least squares vector matching progress with the sub-pixel positioning accuracy,and synchronizes to generate mapping-level accuracy of both 2D and 3D vector results.3?According to the multi-source and measurable images data set,the multi-view images based rendering environment is constructed to provide the user holographic browsing and interactive modeling experiences under 3D real scenes and the precise 3D models of spatial objects by multi-level hierarchical modeling techniques:the aerial oblique images are used to build the intermediate model.The fine models including the side of the buildings and the ground surface landscapes are constructed by mobile image acquisition devices.Based on the combination of tilting camera images and mobile measurement data,which are overcoming the difference of resolution,photography angle and radiating characteristics,the photogrammetry environment based on multi-view images is constructed,and the interactive 3D modeling of spatial objects is provided to user 's holographic browsing and 3D real scenes.4?Through 3D,multi-angle,all-round display technology,the system integrates the land remediation planning elements with remote sensing images as well as DEM(Digital Elevation Model)data and multi-source 3D real images under the unified spatial scale to achieve the linkage of both 2D and 3D data.5 ? According to the implementation of the prototype scale test results and algorithm theory,combined with the more comprehensive data and the latest achievements of the 3D modeling both at home and abroad,the theoretical model will be further improved according to the experimental results of the test.The innovation of this dissertation is briefly summarized as follows:1?Space-surface joint image oriented registration technologyBased on the low-altitude oblique image data of UAV and the surface image data collected by automobile-mounted and back-loaded RTK cameras,the joint method can be used to overcome the difficulties of the traditional air triangulation and the occlusion or discontinuities of the images.The use of graphics processing unit(GPU)parallel algorithm can improve the efficiency of large-scale data equations solution.2?The key technology of accurate real 3D modeling based on space-surface images fusionAccording to the difference among the resolution,photography angle and image radiation characteristics,this dissertation constructs the photogrammetric environment based on multi-view images,and provides the interactive fine 3D modeling under the real 3D environment according to the combination of the oblique photography and the mobile measurement data source with holographic browsing and querying functions.3?The integration of 2D and 3D land consolidation planning and design modeling technology under the real 3D environmentBased on the real 3D modeling technology with the data fusion of space-surface images,the dissertation puts forward a totally new model of real 3D land consolidation planning and designing model,which can wholly change the traditional model based on the artificial measurement and the 2D plane planning and designing way.The real 3D modeling method can improve the efficiency of measurement and planning and designing and enhance the effect of visual display of the project area,which can largely strengthen the application 3D model in the land consolidation planning and designing.