# Detecting Underground Geospatial Features for Protection of Rights in 3D Space: Korean Cases
## 2 Methodology  
In this study, store-level 3D spatial data were generated by conducting a survey and using a pre-built data processing method for underground space registration. By using the two methods in parallel, data can be obtained for an area without pre-built spatial data, by surveying, and 3D spatial data can be generated for an area with pre-built data. After generating the store-level 3D spatial data, underground space registration data were generated as the spatial status information (location, boundary, etc.) for the above and underground space. The data were entered for attribute information necessary for registration as shown in Figure 1.  
Mobile terrestrial LiDAR equipment known as a 3D Mapping Trolley from NavVis was used to acquire data during the survey. This equipment is equipped with an optical digital camera and a laser scanner, and hence, it can easily capture spatial data by acquiring both  
Figure 1: Processes used in this study. point cloud and image data simultaneously. The detailed specifications of the equipment are presented in Table 1.  
In this study, the VWorld data of the Korean Ministry of Land was used as pre-built data to generate 3D spatial data. There were differences in the data format and universality, operable programs, and coordinate systems, as the agents for data generation and management were different. The characteristics of each data are presented in Table 2. VWorld is an open platform for spatial information that is built on the basis of spatial information accumulated by the Korean government and is being serviced through the web. It provides 2D and 3D spatial information free of charge through an open application program interface (API). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Classification** & & **Specification** & **Quantity** & **Product Image** \\ \hline \multirow{8}{*}{Optical Camera} & - & Individual image resolution: 7360 \(\times\) 4912 & \multirow{8}{*}{6} \\  & - & Fisheye 7.5 mm & \\ \cline{1-1}  & - & Full Frame CMOS Sensors & \\ \cline{1-1}  & - & Image aspect ratio:32, 16:9 & \\ \cline{1-1}  & - & Dynamic range function included & \\ \cline{1-1}  & - & Flash synchronization speed: 1/160 s & \\ \cline{1-1}  & - & Camera automatic control and synchronization function & \\ \cline{1-1}  & - & Image log autosave function & \\ \cline{1-1}  & - & Panoramic image autostitich function & \\ \cline{1-1}  & - & Panoramic image: 32 meegujvel supported & \\ \cline{1-1}  & - & Field of view horizontal: 270\({}^{\circ}\) & \\ \cline{1-1}  & - & Angular Resolution: 0.25\({}^{\circ}\) & \\ \cline{1-1}  & - & Rotation Frequency: 40 Hz & \\ \cline{1-1}  & Laser Scanner & - & Usable Range: 30 m & \\ \cline{1-1}  & - & Accuracy: 0–10 m: \textless{}10 mm, 10–30 m: \textless{}30 mm & \\ \cline{1-1}  & - & Laser Safety Class1 & \\ \cline{1-1}  & - & Points per Second 43,200 (1080 \(\times\) 40) & \\ \cline{1-1}  & - & Sensor: IMU, Magnetometer & \\ \cline{1-1} Sensors & - & WiFi: 2.4 + 5.0 GHz, 802.11a/b/g/n/ac & 1 \\ \cline{1-1}  & - & Bluetooth: Bluetooth4.0 LE & \\ \cline{1-1}  & - & Measurement error between two points within 100 m: 20–30 mm & \\ \cline{1-1}  & - & Panorama resolution (stitched): 32 meegujvel & \\ \cline{1-1}  & - & Point cloud: XYZ, Normals & \\ \cline{1-1}  & - & Color from images & \\ \cline{1-1} System Performance & - & Density: up to 5 mm & 1 \\ \cline{1-1}  & - & Point cloud formats: LAS,PLY,PTS,XYZ & \\ \cline{1-1}  & - & Other Outputs: 2D Map & \\ \cline{1-1}  & - & Create Navigation Graph & \\ \cline{1-1}  & - & Create WiFi Fingerprints & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics of surveying equipment.