• Journal of Korean Society for Geospatial Information Science
• /
• v.19 no.4
• /
• pp.13-21
• /
• 2011

The purpose of this study is enhancing CFD model by applying detailed and accurate CFD input data produced from 3D City model and integrating CFD model with 3D city model with OpenGL, 3D city aerodynamic simulation, and visualization tool. CFD_NIMR_SNU model developed by NIMR and SNU and 3D City model produced by NGII were used as input data. Wind flow and pollution diffusion simulator and viewer were developed in this study. Atmospheric environment simulation and visualization tool will save time and cost for urban climate planning and management by enhancing visual communication.

• Proceedings of the KSRS Conference
• /
• 2008.10a
• /
• pp.365-367
• /
• 2008

A digital city model represents a 3D environment of a city with various city object information such as 3D building model, road, and land cover. Usually, at least two satellite images with some image overlap are necessary and a complex satellite-related computation needs to be carried out to create a city model. This is an expensive technique, because it requires many resources and excessive computational cost. The authors propose a methodology to create a digital city model including 3D building model and land cover information from a single high resolution satellite image. The approach consists of image pan-sharpening, shadow recovery, building occlusion restoration, building model extraction, and land cover classification. We create a digital city model using a single KOMPSAT-2 image and review the result.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.249-250
• /
• 2010

The study aims to propose a method that shall rapidly acquire 3D spatial information of the frequently changing city areas by using the low altitude aerial images taken by the UAV. The artificial 3D model of the artificial structures was constructed using the aerial image data photographed at the test area, calibration data of the non-metric camera and the results of the ground control point survey. Also, the digital surface model was created for areas that were changed due to a number of civil works. Through the above studies, the possibilities of constructing a 3D virtual city model, renewal of 3D GIS database, abstraction of changed information in geographic features and on-demand updating of the digital map were suggested.

• Journal of Korean Society of Disaster and Security
• /
• v.9 no.2
• /
• pp.77-86
• /
• 2016

In this study, we have created CityGML based 3D information model for drainage facility, manhole and terrain. It conducted analysis of the rainfall-runoff leak through the information model for obtaining interoperability for information integration between city models. The models have advantages to manage the infrastructure information in point of semantic meaning and geometric information by converting the original 2D GIS construction information into the 3D information model. The input values can be automatically generated through the 3D information model of this study, while the values should be entered manually in the conventional method. Also, it can be useful to check the flooding level and related locations by connecting the result of rainfall interpretation and information model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.4
• /
• pp.347-354
• /
• 2007

Since large portal service providers started web services for 3D city models around the world using spatial imagery, the competition has been getting intense to provide the models with the higher quality and accuracy. The building models are the most in number among the 3D city model objects, and it takes much time and money to create realistic model due to various shapes and visual appearances of building object. The aforementioned problem is the most significant limitation for the service and the update of the 3D city model of the large area. This study proposed a method of generating realistic 3D building models with quick and economical texture mapping using multiple spatial imagery such as aerial photos or satellite images after reconstructed geometric models of buildings from building layers in digital maps. Based on the experimental results, the suggested method has effectiveness for the generation of the 3D building models using various air-borne imagery and satellite imagery quickly and economically.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.1
• /
• pp.47-52
• /
• 2008

The visual implementation of 3-dimensional national environment is focused by the requirement and importance in the fields such as, urban planing, telecommunication facility deployment plan, railway construction, construction engineering, spatial city development, safety and disaster prevention engineering. The currently used DEM system based on the 2-D digital maps and contour lines has limitation in implementation in reproducing the 3-D spatial city. Currently, the LiDAR data which combines the laser and GPS skill has been introduced to obtain high resolution accuracy in the altitude measurement in the advanced country. In this paper, we first introduce the LiDAR based researches in advanced foreign countries, then we propose the data generation scheme and an solution algorithm for the optimal management of our 3-D spatial u-City construction. For this purpose, LiDAR based height data transformed to DEM, and the realtime unification of the vector via digital image mapping and raster via exactness evaluation is transformed to make it possible to trace the model of generated 3-dimensional model with long distance for 3D u-city model generation.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.1174-1176
• /
• 2003

Recently 3D city models are required for many applications such as urban microclimate, transportation navigation, landscape planning and visualization to name a few. The existing 3D city models mostly target on modeling buildings, but vegetation also plays an important role in the urban environment. To represent a more realistic urban environment through the 3D city model, in this research, an investigation is conducted to extract the position of trees from high resolution IKONOS imagery along with Airborne Laser Scanner data. Later, a tree growth model is introduced to simulate the growth of trees in the identified tree-positions.

• Spatial Information Research
• /
• v.20 no.4
• /
• pp.1-16
• /
• 2012

There is no doubt that the urban heat island (UHI) is a mounting problem in built-up environments, due to energy retention by the surface materials of dense buildings, leading to increased temperatures, air pollution, and energy consumption. To investigate the UHI, three-dimensional (3-D) information is necessary to analyze complex sites, including dense building clusters. In this research, 3-D building geometry information is combined with two-dimensional (2-D) urban surface information to examine the relationship between urban characteristics and temperature. In addition, this research introduces spatial regression models to account for the spatial spillover effects of urban temperatures, and includes the following steps: (a) estimating urban temperatures, (b) developing a 3-D city model, (c) generating urban parameters, and (d) conducting statistical analyses using both Ordinary Least-Squares (OLS) and Spatial Regression Models. The results demonstrate that 3-D urban characteristics greatly affect temperatures and that neighborhood effects are critical in explaining temperature variations. Finally, the implications of the results are discussed, providing guidelines for policies to reduce the UHI.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.3
• /
• pp.50-54
• /
• 2009

Recently, many researches have been conducted to develop 3D Indoor/Outdoor Spatial Data Models. The 3D data created based on these data models have complex data structures. In order to manage these data efficiently, it is better to use a DBMS. There have been many researches to maintain the 3D data in Geo-DBMS, such that Oosterom (2002) and Arens (2005) developed a method to store 3D Building model, geometric and topological data of coverage in DBMSa. In this study, we propose a method to store the CityGML data into the RDBMS, Oracle Spatial 11g.

• Korean Journal of Remote Sensing
• /
• v.24 no.2
• /
• pp.179-188
• /
• 2008

This study aims for generating a city spatial model required for the creation of a 3D noise map. In this study, we propose an efficient method to generate 3D models of the terrain and buildings using only a digital map and draft maps previously established without using any sensory data. The terrain model is generated by interpolating into a grid the elevation values derived from both the contour lines and the elevation point of the digital map. Building model is generated by combining the 2D building boundaries and the building elevations extracted from the digital map and the draft map, respectively. This method has been then applied to a digital map and three sets of draft maps created in the different times. covering the entire area of Yeongdeungpo-gu. The generated city spatial model has been successfully utilized for the noise analysis and the 3D visualization of the analysis results.