Study Of The Application Of GNSS System Integrated Multi-Beam Technology In The Survey Around The Waters At Leshan Giant Buddha

Underwater topographic survey is the basic work of many water conservancy projects,which is very important in the development and utilization of rivers,lakes and oceans.In general,the underwater topographic survey need to measure plane coordinate points on the surface of the water using the surveying vessel,meanwhile to measure depth of underwater using sounder,and to obtain three-dimensional coordinates points of underwater terrain by combining this two methods,and then obtain the final underwater topographic map.There are many methods to measure the point's coordinate on the water surface.It is recommended to adopt the method of GNSS positioning.Compared with other positioning methods,GNSS has many advantages,such as real-time,all-weather,high precision and so on,and this positioning technology has been widely used in many fields,such as navigation,surveying and mapping,communication and etc.Many methods are used to measure the depth of the water,which is recommended to use multi-beam.The multi-beam measurement is measuring is very fast and efficient in scanning the area.Therefore,in this study,the application of GNSS technology and multi-beam depth sounder in underwater topographic survey has been carried out,and several problems have been studied and analyzed in depth.This paper mainly researched on the waters exploration project of the Leshan Giant Buddha.Through deep analysis.In this paper,in order to study the Multi-technique integration application problems that GNSS positioning technology combined with water multi-beam technology,side scan sonar technology as an auxiliarytechnology,and the study is carried out.This article mainly takes the Leshan Giant Buddha water exploration project as an example.The main task of the study is the erosion and erosion of the underwater bank slope of the Leshan Giant Buddha and the thickness of the river bottom cover.The survey focus on the use of underwater exploration and photography technology to detect underwater photography specific circumstances.This paper analyzes and studies the principle of GNSS positioning,including static relative positioning,real-time dynamic measurement positioning principle and method,meanwhile analyzes the main sources of error of the measurement system,and puts forward some solutions to reduce or eliminate the error according to the characteristics of the project.In addition,for underwater measurement tasks,multi-beam measurement techniques are studied,includingpositioning principle,equipment installation and calibration,data processing and other aspects.The solution to the problem is proposed according to the causes of errors in each link.Taking the data collection of Leshan Giant Buddha waters as an example,we design the data acquisition scheme in this area,and select the equipment used for data acquisition and install the calibration method and make the sounding line and the measuring method.Through the data processing,we get the data accuracy and reliability index and assess the quality of underwater topographic survey results.Finally,the accuracy of the measurement accuracy of GNSS positioning on the river is0.62 m,and the accuracy of depth measurement is 0.122 m.Through the use and case analysis of GNSS technology and multi-beam sounding technology,the advantages of the two technologies are found,and the future technology of underwater mapping is prospected.With the professional software,multi-beam measuring results can be shown well,and with 3D digital terrain model,we can get the more clear,detailed situation about underwater terrain.