Integration And Realization Of Three-Dimensional Integrated Measuring System For Water And Land

There are many rivers in China,and they are widely distributed.Many rivers play an important role in waterway transportation.In order to ensure that the river channel plays its role normally,the stability of economic construction is guaranteed,it is essential for the construction and maintenance of river courses,obtaining the topographic data of the river has always been the basis of river maintenance work.In the traditional river survey work,GPS-RTK(Global Positioning System-Real Time Kinematic)is used together with the total station to measure the river bank,and the single beam sounder is used to map the underwater terrain.This method is affected by factors such as complex river environment and poor measurement conditions,and its operation efficiency and accuracy are not high.How to obtain accurate water and underwater terrain data efficiently and quickly has always been a difficult point for surveyors.Aiming at some practical problems existing in current river channel and navigation channel mapping,the solution model of water-land integrated measurement system is proposed,which is the non-contact,high-speed,high-precision measurement advantages of mobile 3D laser scanner and multi-beam sounder.GNSS(Global Navigation Satellite System),attitude instruments and other instruments can achieve rapid measurement of river banks and underwater terrain at the same time.It can directly acquire point cloud data of a large number of terrains and map topographic maps,which is of great significance to the construction and maintenance of river courses.This paper first introduces the advantages and principles of 3D laser scanners and multibeam depth sounders.For the case where the coordinate system of the data between different sensors of the system is not uniform,using the position and attitude data provided by GNSS and the attitude meter in real time,through the derived coordinate transformation matrix,the conversion and unification of different sensor data coordinate systems to the engineering coordinate system are realized;Inconsistent time system for different sensor data of the system,in this paper,the time synchronization method is used for time unification,and 1PPS(1 Pulse Per Second)is used as the time synchronization controller to realize the time uniformity between the system sensor data;Aiming at the particularity of hydrological measurement,a non-test tide sounding technology based on EGM2008(Earth Gravitational Model 2008)gravity model is proposed to realize the system's elevation conversion,and the conversion accuracy is analyzed to confirm the feasibility of the model.Then it analyzes the error sources of the system in detail,summarizes the errors of the 3D laser scanner and the multibeam sounder,analyzes the influence of various errors on the system data,and takes measures to correct the different errors.By correcting the error,the reliability of the measured data is greatly improved.Finally,using the integrated system to collect data in the field to evaluate the accuracy of the system,verify the feasibility and reliability of the integrated land and water measurement system.It is proved by engineering experiments that the shipborne 3D laser scanner and the multi-beam sounder integrated water-land integrated 3D measurement system are completely feasible for the simultaneous acquisition of water and underwater terrain data.Compared with the traditional mapping technology,the integrated land and water measurement system can greatly improve the efficiency of mapping,reduce the consumption of manpower and material resources,and the working environment will be more secure.