韩国智能城市将3D数字模型与GIS和BIM结合在一起

Author: Linda Duffy

Around the world, local governments are rolling out Smart City/Digital Twin projects to support economic stimulation and tourism programs and to improve the quality of life overall. Up-to-date 3D building models and comprehensive Geographic Information Systems (GIS) data, along with Building Information Modelling (BIM) data, are combined to create a digital twin of the inside and outside of buildings and the surrounding topography. In effect, the real world is converted into an exact digital replica to facilitate analysis, planning and management of all smart city assets.

3D虚拟城市背后的主要目标是通过对数字双胞胎进行模拟和分析并利用结果改善条件来减少和管理通常在城市地区发现的问题。此外，用物联网（IoT）传感器，闭路电视（CCTV），安全摄像机等捕获的大数据提供了对特定位置的见解。韩国政府于2017年启动了其智能城市/数字双胞胎计划，以解决各种问题，例如交通，犯罪，环境污染，有效的能源管理，城市规划，灾难管理和重建。通过分析虚拟城市和相关的大数据，政府实体可以更好地解决问题。

Building a digital twin

All4Land, a leading geospatial service provider in South Korea, has been building 3D digital models that include BIM and GIS data since 2014. To save time and reduce cost, All4Land collects oblique and LiDAR data simultaneously with itsLeica CityMapperairborne mapping sensor and quickly processes the data withLeica HXMAP, a multi-sensor processing platform. The resulting 3D models are enhanced with GIS data, such as vector maps of utilities, telecommunication, or transportation infrastructures, to support in-depth analysis. The external shapes of buildings are made from CityMapper data and the internal shapes are made from 3D scanning data, design data and BIM data.

All4Land is responsible for creating the GIS data and 3D building models and integrating BIM data provided by the building owner or a government agency. BIM data is mandatory for new government construction in Korea and is normally produced by a 3rd party design office. For new buildings, BIM is typically captured during and after the construction process, and for existing buildings it is established by reverse engineering with 3D scanning and original design data.

结合CityMapper和HxMap解决方案提供s automatic processing at Level of Detail 1 (LOD1) and LOD2 based on CityGML, an open data model and XML-based format for the storage and exchange of virtual 3D city models. LOD3 requires some manual processing to express open elements like gates and windows, and LOD4 involves manual processing that depends on the level of indoor details.

“ HXMAP中有强大的功能，尤其是在用于多个相机的同时进行空气三角调节处理中，以及来自图像和激光雷达数据的有效3D建模，” All4land董事总经理Sangkwam Nam说。“ HXMAP还支持处理任务，例如传感器校准，自动点匹配，线路对线注册，建筑生成等。所有这些都是以前乏味的手动任务，现在可以在HXMAP工作流程中自动运行。”

To combine CityMapper data with BIM data, All4Land first allocates coordinates derived by GNSS surveying to the BIM data, then converts the BIM data to 3D building models and merges them with CityMapper data. All4Land developed its own proprietary software for data conversion and coordinate allocation and makes the 3D models available through its MapPrime platform, a WebGIS server that integrates indoor and outdoor models and provides data visualisation tools.

CityMapper LiDAR Point cloud (Point density : 25 point/㎡)

Jeonju’s 3D model

In 2019, with its purchase of a highly efficient CityMapper aerial system and HxMap, All4Land became well-positioned to expand its 3D mapping services. Collecting data quickly is particularly important because of the unique limitations of aerial data capture in South Korea. Surrounded by the sea on three sides, cloud cover in South Korea frequently creates unfavourable weather conditions. In addition, it is difficult to get flight permission near military zones and security areas, therefore total flying days are quite limited. Under these circumstances, the CityMapper’s ability to capture orthophotos, oblique imagery and LiDAR all in one flight is advantageous.

“The CityMapper is an excellent solution for our projects ─ the added efficiency allows us to capture more data in a shorter period of time,” says Nam. “And HxMap streamlines the processing and modelling, which reduces the cost of building a digital twin.”

One of the test projects for the Digital Twin concept was in the city of Jeonju, a tourist area in North Jeolla Province in southwestern South Korea. Many historic buildings, such as the traditional village called Hanok, attract visitors, and the city is known for its excellent regional cuisine. Recently Jeonju introduced the Digital Twin concept as part of MaaS (Mobility as a Service) to attract tourists and help them travel around the city using electric bicycles, electric kick boards, and other transportation.

All4Land was selected to conduct two projects in Jeonju, first mapping an area 4 square kilometres (sq km) in size, including BIM for 20 buildings, followed by a 205 sq km project. The City of Jeonju and LX, the government cadastral organisation, are in the process of acquiring BIM data for all government-owned buildings in the larger area. Using CityMapper, aerial data capture of the large project took All4Land only two days, with an additional two to three months for data processing and 3D building modelling. The LOD3 outdoor data captured with the CityMapper were merged with indoor BIM data in the test area to create an LOD4 model of the real world.

“数字双胞胎对许多应用都有帮助，” NAM说。“例如，在计划在市中心地区的新建筑物之前，模拟模型被用于分析360度视图，可见性范围，太阳权权利，隐私问题等。这发现了与现有建筑物的任何潜在冲突。可以在早期阶段修改和改进开发计划，从长远来看节省资金。”

3D建筑模型

Smart cities are the future

当今韩国大约有十个智能城市项目，预计数量将增加。除全地外，All4land还在为韩国首尔市的虚拟首尔项目和韩国国家地图局（NGII）的3D地理空间项目（NGII）致力。

韩国智能城市将基于智能流动性，人口统计，旅游业和其他因素而着重于当地经济的生命。政府组织使用3D建筑模型来分析支持决策的选择和机会。将来，All4land希望Mapprime平台向商业公司开放，以管理设施，停车，观光等。

数字双胞胎的扩大使用依赖于三维ent collection of data and highly automated processing to keep costs reasonable. Leica CityMapper, and the more recent CityMapper-2, are high-performance urban mapping sensors ideal for fast digitisation of cities and urban environments. The hybrid oblique imaging and LiDAR solutions, paired with the HxMap processing platform, together provide high productivity and fast turnaround.

“We are very satisfied with the CityMapper’s performance and data quality ─ the nadir and oblique images and LiDAR are excellent. We also feel that technical support and training programs offered by Leica Geosystems are the best,” says Nam. “Leica Geosystems keeps supporting customers, trying to find better solutions together during the entire process of operation and processing, and that helps us stay competitive in a rapidly changing industry.”

CityMapper LiDAR Point cloud (Point density : 25 point/㎡)