The Application Of Cadastral Expression In The Urban Underground Space Bassed On Ground-based Laser Scanning Technology

With the rapid economic development, underground space as an important resource has got a certain degree of development and utilization.Land not only extends the range in a plane, and extend vertically up and down underground. This trend allows developers to use the land exhibits three-dimensional features, land use by the two-dimensional plane parcel into the underground extension of the three-dimensional space. The expression of these three-dimensional space has become the main issues we are concerned.However, due to the special nature of the underground space mapping environment, coupled with the current laws and regulations did not complete its specification, we did not know what technology and what method to use to collect data of underground space of the building can be used.How to correctly express underground space has no written conclusions, leading to many problems in the development and utilization of underground space.With the three-dimensional laser scanning technology matures, the use of three-dimensional laser scanner that geting point cloud data, and process different data throwing processing software to analysis and enable 3D reconstruction of objects has become an important tool, it has been widely used in the field of ancient heritage, topography surveying, digital city, reverse engineering, landscape reconstruction and so on.This article uses the terrestrial laser scanning technology for underground space research, The main contents are as follows:Fist, the characteristics of underground space and underground space buildings were definited, and describes the common methods of urban underground space data acquisition, and details of the acquisition of data based on terrestrial laser scanner process of urban underground space;Two, three dimensional laser point cloud data acquisition was pretreated, extracted underground space data required for three dimensional modeling, and established a three dimensional physical model of the underground space of the building according to the various components of the building;Third, from a legal perspective, three dimensional layered aspect angle, angle in space and topological relations between the underground buildings and others to study the expression of underground space cadastre; Draw a three-dimensional map of underground space of the building and two-dimensional plan; Extract the boundary point coordinates, boundary edge length, demonstrate terrestrial laser scanning technology for urban underground space cadastral feasibility and accuracy of expression by errors analysis of the whole process.