Real-time 3D Model Construction And Precision Analysis Based On Tilt Photogrammetry

“Real 3D China” has become the focus of attention in the preparation of the“14th Five-Year Plan”,the tilt photogrammetry based on the new imaging system has been widely concerned and developed rapidly with its unique advantages,and has become a new technical means in the field of surveying and mapping.The multi-view image captured by tilt photography has rich texture information,which satisfies the requirements of the real-world 3D model to construct the image,and makes the 3D model become a new data bearing form of photogrammetry,which also gives birth to a new mapping method.At the same time,the accuracy of mapping based on 3D model is higher than that of traditional stereo mapping.Combining engineering examples,this paper firstly compares the precision difference between stereoscopic model and 3D model based on straight image,then studies the difference of precision between 3D models based on straight image and oblique image.Then the effects of image control point layout,POS assist,image ground resolution and zoning adjustment on the accuracy of tilted photogrammetry are analyzed.Finally,the accuracy difference between tilted photogrammetry and straight photogrammetry for real shot image is summarized.and finally summarizes the difference in accuracy between tilted photogrammetry and stereophotometry.The main works of this paper are:(1)Based on the traditional vertical photogrammetry,the plane and elevation accuracy of the stereoscopic model and the 3D model are compared experimentally.It is verified that the accuracy of multiple pieces of forward intersection is significantly better than that of two pieces of forward intersection;(2)Combining the measurement areas of two different terrains,the difference between plane and elevation precision of 3D model based on straight and oblique images is analyzed and compared.The results show that the accuracy of tilt photogrammetry is higher than that of vertical photogrammetry;(3)Combined with engineering examples,the effects of different image control point layout schemes,POS information assisted aerial triangulation,and different image ground resolutions and zoning adjustments on the accuracy of 3D models were studied.The results show that the arrangement of one image control point every six navigation belts can meet the accuracy requirements of the 1:500 topographic map of the mountain,and the elevation accuracy can be further improved every threenavigation belts;adding POS information can effectively improve the plane accuracy of the corner,but has little effect on the ground checkpoint;after the image ground resolution is increased from 1.5cm to 1cm,the plane angle of the corner checkpoint is improved by about 1 time;joint adjustment does not significantly improve the plane accuracy of the model,but can significantly improve the elevation accuracy of the overlap region.(4)Combining different terrain measurement areas and using two common commercial softwares to conduct experiments,the differences between image processing quantity and mapping accuracy of the two softwares are summarized.The results show that the accuracy of TDOM based on tilted images is slightly higher than that of the straight images.