• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.229-240
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• 2019

3D geo-spatial model have been widely used in the field of Civil Engineering, Medical, Computer Graphics, Urban Management and many other. Especially, the demand for high quality 3D spatial information such as precise road map construction has explosively increased, MMS and UAV techniques have been actively used to acquire them more easily and conveniently in surveying and geo-spatial field. However, in order to perform 3D modeling by integrating the two data set from MMS and UAV, its so needed an proper registration method is required to efficiently correct the difference between the raw data acquisition sensor, the point cloud data generation method, and the observation accuracy occurred when the two techniques are applied. In this study, we obtained UAV point colud data in Yeouido area as the study area in order to determine the automatic registration performance between MMS and UAV point cloud data using ICP(Iterative Closet Point) method. MMS observations was then performed in the study area by dividing 4 zones according to the level of overlap ratio and observation noise with based on UAV data. After we manually registered the MMS data to the UAV data, then compared the results which automatic registered using ICP method. In conclusion, the higher the overlap ratio and the lower the noise level, can bring the more accurate results in the automatic registration using ICP method.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.47-50
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• 2007

Since world coordinate system is entirely used because of the revision of land surveying law, it is needed that transformation of coordinates of geo-spatial information established by korea coordinate system to be performed. It is required, however, to have a plan for transformation of world coordinate system because the coordinate system is not unified due to the geo-spatial information system using dualistic control data of both old and new data of korea coordinate system. For this purpose, in this study, I have calculated coordinate transformation coefficient per control data of korea coordinate system and proposed a plan of transforming a dualistic coordinate system which is based on control data of korea coordinate system effectively into world coordinate system through verification of accuracy of transformation per control data.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.353-366
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• 2022

Spatial estimation of geoscience data (geo-data) is challenging due to spatial heterogeneity, data scarcity, and high dimensionality. A novel spatial estimation method is needed to consider the characteristics of geo-data. In this study, we proposed the application of Gaussian Mixture Model (GMM) among machine learning algorithms with multivariate data for robust spatial predictions. The performance of the proposed approach was tested through soil chemical concentration data from a former smelting area. The concentrations of As and Pb determined by ex-situ ICP-AES were the primary variables to be interpolated, while the other metal concentrations by ICP-AES and all data determined by in-situ portable X-ray fluorescence (PXRF) were used as auxiliary variables in GMM and ordinary cokriging (OCK). Among the multidimensional auxiliary variables, important variables were selected using a variable selection method based on the random forest. The results of GMM with important multivariate auxiliary data decreased the root mean-squared error (RMSE) down to 0.11 for As and 0.33 for Pb and increased the correlations (r) up to 0.31 for As and 0.46 for Pb compared to those from ordinary kriging and OCK using univariate or bivariate data. The use of GMM improved the performance of spatial interpretation of anthropogenic metals in soil. The multivariate spatial approach can be applied to understand complex and heterogeneous geological and geochemical features.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.146-160
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• 2020

In the 4th industrial revolution, research on solving urban problems using ICT technology is emerging. Representatively, research is being conducted mainly focusing on smart cities. 3D geo-spatial. Various case studies on smart cities are being conducted to solve urban problems, and in order to effectively implement smart cities, it is implemented on the basis of a digital twin interconnecting physical and virtual environments. To implement a digital twin, the concept of space is essential, and spatial information that composes the real world is also essential. Therefore, in order to implement the digital twin, this study conducted a study on the construction and modeling of 3D geo-spatial information based on the national spatial information establishment regulations and the international standard CityGML for buildings, water facilities, and transportation facilities in Jeonju. In Jeonju, the research area, the LOD was defined, and the possibility of digital twin based on geo-spatial information was determined through data collection, analysis, and construction for each detail. In this study, it is meaningful that a plan to construct geo-spatial information for the implementation of a digital twin is presented, and the result of the construction is modeled as an urban standard model. The results of study are expected to be used as reference for detailed construction plans and standard establishment by governments and local governments promoting smart city and digital twin construction in the future.

• Korean Journal of Remote Sensing
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• v.23 no.3
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• pp.161-169
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• 2007

A study was conducted in the Hong Kong with the aim of deriving an algorithm for the retrieval of suspended sediment (SS) and sea surface salinity (SSS) concentrations from Aqua/MODIS level 1B reflectance data with 250m and 500m spatial resolutions. 'In-situ' measurements of SS and SSS were also compared with coincident MODIS spectral reflectance measurements over the ocean surface. This is the first study of SSS modeling in Southeast Asia using earth observation satellite images. Three analysis techniques such as multiple regression, linear regression, and principal component analysis (PCA) were performed on the MODIS data and the 'in-situ' measurement datasets of the SS and SSS. Correlation coefficients by each analysis method shows that the best correlation results are multiple regression from the 500m spatial resolution MODIS images, $R^2$= 0.82 for SS and $R^2$ = 0.81 for SSS. The Root Mean Square Error (RMSE) between satellite and 'in-situ' data are 0.92mg/L for SS and 1.63psu for SSS, respectively. These suggest that 500m spatial resolution MODIS data are suitable for water quality modeling in the study area. Furthermore, the application of these models to MODIS images of the Hong Kong and Pearl River Delta (PRO) Region are able to accurately reproduce the spatial distribution map of the high turbidity with realistic SS concentrations.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.466-469
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• 2005

In this study e-map component was designed and developed to possibly overlay with all kinds of thematic maps in various scales and provide the all detailed information by using high-resolution satellite image and GIS. Also, this system has powerful map composition tool to display map such as legend, scale bar, index map and so on. For this, this e-map component was designed by using UML and developed based on Windows 2000 and implemented by using Visual Basic 6.0 as development programming language, Map Objects 2.1 of ESRI as GIS component. Through this system, the forest officials could generate more detailed topography and desired thematic map. In addition, the data consistency in DBMS could be maintained by using SDE (Spatial Database Engine) for their job and share the standard forest database with others in real time.

• Spatial Information Research
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• v.23 no.3
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• pp.91-100
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• 2015

We developed a micro UAV based rapid mapping system that provides geospatial information of target areas in a rapid and automatic way. Users can operate the system easily although they are inexperienced in UAV operation and photogrammetric processes. For the aerial data acquisition, we constructed a micro UAV system mounted with a digital camera, a GPS/IMU, and a control board for the sensor integration and synchronization. We also developed a flight planning software and data processing software for the generation of geo-spatial information. The processing software operates automatically with a high speed to perform data quality control, image matching, georeferencing, and orthoimage generation. With the system, we have generated individual ortho-images within 30 minutes from 57 images of 3cm resolution acquired from a target area of $400m{\times}300m$.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.721-724
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• 2005

In this study the spatial distribution characters of forest in forest damaged area were first considered by analyzing spatial data and monitoring forest landscape. Then suitable tree species on each site were selected through the weighted score analysis of GIS analysis methods. Finally, the best forest stand arrangement method could be presented on the 3D based simulation system for the advanced reforestation technology in Korea. For this purpose, the virtual reforestation system was implemented by using the concept of virtual GIS and CBD (Component Based Development) method. By use of this system the change offorest landscape of burnt forest area some years after reforestation practice could be detected and monitored by applying the site index and 3D modeling method.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.19-26
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• 2002

To provide 3D GSIS data on the internet, 3D data structures need to be researched and applied for spatial analysis for subsurface modeling. As for GSIS software R&D trend the following things have pointed out : 3-dimensional geo-processing technologies, internet-based application system development, distributed processing technologies for large volume of spatial information, real-time geo-data processing methodologies, Among them research scope within Internet-based application system or Web-based GSIS generally contains core parts of software development such as Internet application, large volume of spatial database handling, real-time spatial data processing, spatial data transfer and transformation, and volumetric display of processing results. This study shows the method of providing 3D GSIS on the internet using VRML model, which are made of DEM data, draped aerial photo, and VRML script programming. And it is also studied that offering 3D GSIS engine on the internet and precise texture mapping using satellite image and aerial photos.

• Spatial Information Research
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• v.23 no.6
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• pp.43-55
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• 2015

Currently, each organization has developed its gridded data in the form of respective grid system for its own purpose. Interoperability among the organization had been limited and resulted in inconvenient data access and application across domains. In this study, we investigated potential standards for National grid system and their strength and weakness. We also reviewed existing gridding schemes and had a survey of demand about grid system to those who have used or would plan to use gridded data in academic and business sectors. As the result of survey of demand, we suggested national grid system for national grid data integration management system which has the mutual compatibility and also proposed sharing scheme of the grid type for users who need to grid data.