• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.6_2
• /
• pp.969-977
• /
• 2022

Currently, in Korea, aerial photogrammetry is being studied for cadastral boundaries and numerical maps. Since the announced value of cadastral survey is closely related to ownership, the accuracy and reliability of the published value should be emphasized above all else. However, although aerial photogrammetry has great advantages in economic feasibility and surveying efficiency, it has many limitations when extracting the boundary of cadastral survey based on the acquired image. In order to improve these limitations, in this study, an aerial target was applied to obtain reliability improvement. Therefore, in order to examine the usefulness of aerial photogrammetry for cadastral survey application, cadastral boundary extraction and accuracy comparison analysis were conducted.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.4_2
• /
• pp.687-696
• /
• 2023

In recent construction sites, digital maps obtained through drone photogrammetry have garnered increasing attention as indispensable tools for effective construction site management. the strategic placement of Ground Control Points (GCPs) is crucial in drone photogrammetry. Nevertheless, the manual labor and time-intensive nature of GCP surveying pose significant challenges. The purpose of this study is to design the concept of automated GCPs survey technology for enhancing drone photogrammetry efficiency in construction sites. As a result, the productivity of the automated method was analyzed as 118,894.7㎡/hr. It is over 25% productivity improvement compared to traditional methods. In future studies, economic analysis of automated methods should be studied.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.6_2
• /
• pp.1063-1071
• /
• 2023

Unmanned aerial vehicles (UAVs, drones) are becoming increasingly useful in a variety of fields. Advances in UAV and camera technology have made it possible to equip them with ultra-high resolution sensors and capture images at low altitudes, which has improved the reliability and classification accuracy of object identification on the ground. The distinctive contribution of this study is the derivation of sensor-specific performance metrics (GRD/GSD), which shows that as the GSD increases with altitude, the GRD value also increases. In this study, we identified the characteristics of various onboard sensors and analysed the image quality (discrimination resolution) of aerial photography results using UAVs, and calculated the shooting conditions to obtain the discrimination resolution required for reading ground objects.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.6
• /
• pp.579-586
• /
• 2019

The national base map of Korea has become more useful as the spatial information industry has developed rapidly. Beyond the simple application of the past paper map era, the role as important spatial information in the smart city and digital twin era is required with the IT (Information Technology) revolution. Therefore, the concepts of seamless, multi scale, object-oriented, customized production and real-time updating have emerged, and innovations in the distribution process through the internet are also taking place. Although the concept and definition in the law that is corresponds to the status of the national base map must be supported, the concept and definition of the paper map introduced from the surveying law in 1980 still exist. The definition of the national base map cannot meet current technological developments and social needs and does not reflect the perceptions of the majority of the people as well as the practical capacity of government organizations that manage it. Therefore, it is necessary to establish the concept of national base map in accordance with the current situation and to define it in the law. In this study, the concept of national base map was established and defined by comprehensive analysis of the development process of the national base map, the changes in the times and cases of the United States, the United Kingdom and Japan.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.5
• /
• pp.551-560
• /
• 2014

Compare to other industrial sites, the civil construction work not only takes longer time but also has made of complicated processes, such as the integrated management, process control, and quality control until the completion. However, it is hard to take control the construction sites, since numerous issues are always emerged. The study purposes on providing the dataset to synthetically manage and monitor the civil construction site, main design, drawings, process, construction cost, and others at real-time by using the low altitude close-range aerial images, based on UAV, and the GPS surveying method for treating the three-dimensional spatial information quickly and accurately. As a result, we could provide the latest information for the quick decision-making following from planning to completion of the construction, and objective site evaluation by the high-resolution three-dimensional spatial information and drawings. Also, the present map, longitudinal map, and cross sectional view are developed to provide various datasets rapidly, such as earthwork volume table, specifications, and transition of ground level.

• Journal of Broadcast Engineering
• /
• v.17 no.2
• /
• pp.411-421
• /
• 2012

The stagnant growth in 3D market due to 3D movie contents shortage is encouraging development of techniques for production cost reduction. Elimination of vertical disparity generated during image acquisition requires heaviest time and effort in the whole stereoscopic film-making process. This matter is directly related to competitiveness in the market and is being dealt with as a very important task. The removal of vertical disparity, i.e. image rectification has been treated for a long time in the photogrammetry field. While computer vision methods are focused on fast processing and automation, photogrammetry methods on accuracy and precision. However, photogrammetric approaches have not been tried for the 3D film-making. In this paper, proposed is a photogrammetry-based rectification algorithm that enable to eliminate the vertical disparity precisely by reconstruction of geometric relationship at the time of shooting. Evaluation of proposed algorithm was carried out by comparing the performance with two existing computer vision algorithms. The epipolar constraint satisfaction, epipolar line accuracy and vertical disparity of result images were tested. As a result, the proposed algorithm showed excellent performance than the other algorithms in term of accuracy and precision, and also revealed robustness about position error of tie-points.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.3
• /
• pp.1-9
• /
• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• Journal of Cadastre & Land InformatiX
• /
• v.49 no.2
• /
• pp.123-134
• /
• 2019

The introduction of the world geodetic reference system in cadastral sector can apply the international standardization of cadastral survey and can be the basis for the creation of new industries by merging with other industries based on spatial information. With the introduction of the world geodetic reference system, non-coincidence land may cause problems which are whether the cadastral record and the real estate register are not consistent, etc. This problem infringes on the protection of ownership of citizens suggested in the main purpose of ｢Act On The Establishment, Management, Etc. Of Spatial Data｣. We have analyzed at overlapping cases between private land and overlapping cases between national and public land and suggested institutional improvement measures to solve problems arising on the site. As a result, it will be necessary to introduce a transformation verification measure by the world geodetic reference system in order to assign a function as a cadastral records to mapping converted to the world geodetic reference system. It is also expected that the legal and institutional basis should be established for alert adjustment and positioning through verification measures. Finally, it is difficult to determine the transformation factor as the co-ordinates of common points also differ because survey results vary by work area. Therefore, it is deemed necessary to consider the requirement to use the cadastral measurement basis by the world geodetic reference system in 2021.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.4
• /
• pp.213-221
• /
• 2018

South Korea has been reluctant to open its geospatial information overseas to ensure security as a divided country. However, this cannot continue as the domestic and international environments related to geospatial information and the industrial ecosystem of information and communication technologies have been changing dramatically. Within this context, this study aims to analyze the causal relations among relevant variables and how they change and interact with time using a systems thinking process. First, causal maps were created for the domains of national security, map-based convergence service, and corporate competition. Then, the causal maps for each domain were integrated, based on which the points for policy intervention and dominant feedback loops were identified. The analysis results showed that securing the self-sufficiency of domestic geospatial businesses is a key element to determine the whole causal map, and the variable that changes the dominant feedback loop from a vicious circle to a virtuous one is the decision to open geospatial information overseas. In this study, I found the policy leverage that is a policy intervention point that can produce a great effect with little input by building a causal map of the interactions between major variables. This study is significant in that it identified and analyzed the dominant feedback loop as to which causal structure would dominate the system in the long term. The results of this study can be used to discuss not only the impacts of map data overseas opening on the national security and geospatial information industry, but also the interactions in the future when Google or other global companies request to release the geospatial information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.6
• /
• pp.417-426
• /
• 2019

Conventional visualization of PM (Particulate Matter)10 flows applies superimposition of concentration distribution maps and wind field maps. This method is efficient for small scale maps where only macro flow trends are of interest. However, in the case of urban areas, local flows are difficult to model at micro level using wind fields, and therefore different methods of flow extraction is deemed necessary. In this study, flow information is extracted and visualized directly from the PM10 density data by using the gravity model. This method has the advantage that additional information such as wind field is not necessary for estimating the intensity and direction of PM10 flow. The extracted spatio-temporal flow patterns of PM10 are analyzed with relation to traffic information.