Research On The Urban3D-GIS Real Data Collection And Processing Technique

With the rapid development of information technology in our country, the traffic, infrastructure construction and other pressure of the city are gradually increasing, in order to better the construction and development of city informatization foundation, in succession have appeared mobile3DGIS real data collection system; The main sensors include CCD image acquisition system, Global Positioning System (GPS), Inertial Measurement Unit (IMU) and Laser Scanner(LS), which are loaded on the mobile(such as motor vehicles); when the mobile is moving forward at a certain speed, fast collection and processing of city space3D real data, to form an effective3DGIS real traffic management information platform; The real data collection system not only provides a convenient, economical way of working, further more be good to meet the construction demand of GIS information database in city intelligent traffic management system.This paper summarizes research status of the current mobile3DGIS real data collection system, through mobile3DGIS real data collection system as the basic platform; describes the system structure of the platform, detailedly analyses the working principle of data acquisition and the basic work flow of system.Focus on the system pretreatment technology of3D real data collection front: Firstly, analyses the basic principle of CCD panoramic sensor system, to achieve the calibration of CCD through based on RAC calibration algorithm, obtained the internal and external parameters of camera, effective implementation of the city3D real image acquisition. Then, clarifies using GPS/IMU navigation to provide positioning and orientation information for the whole system, this paper proposes a new data filtering processing algorithm, completed the filter processing of the data of GPS and IMU, the system platform space position, correct posture and speed and the other information, to improve the accuracy of integrated navigation system. Finally, analysis the sensors of the system, the data acquisition frequency and spatial coordinates are different; the temporal alignment of basic research; time registration mainly adopts synchronous to the GPS time system, through the combination of hardware and software to achieve, through the conversion of space coordinate system to achieve the CCD image sensor, three laser scanner registration to GPS space coordinate system as the base of the spatial coordinate system, and gives the coordinate transformation parameters of each sensor; the ultimate guarantee of synchronization of multiple different sensors between3D spatial data in time and space; to improve the validity and reliability of mobile3DGIS real data collection system.Based on the data processing method, under the environmental condition of the city3DGIS real data collection system is designed in this paper, the system of city space three-dimensional streetscape acquisition made certain practical application, laid the foundation for the following research.