UAV 사진측량기반 3D 모델을 이용한 지적재조사사업 적용 가능성 연구 : 울산광역시 서부4 지적재조사지구를 대상으로

UAV 기반 3차원 모델을 지적재조사 경계 확인에 적용할 가능성을 분석했다.

This study analyzed the applicability of a UAV photogrammetry-derived 3D model as a boundary verification tool for the cadastral resurvey project in a densely built urban residential area. The study focused on the Seobu 4 Cadastral Resurvey District in Ulsan, Korea, where densely distributed buildings, narrow alleys, retaining walls, and severe occlusions limit the effectiveness of conventional ground surveying and 2D image-based boundary verification methods. To overcome these limitations, UAV imagery was acquired using a combined flight strategy of vertical and oblique photography with a double-grid flight pattern and high image overlap.

A mesh-based 3D model was generated using Structure from Motion (SfM) and Multi-View Stereo (MVS) techniques. Positional accuracy was evaluated using Ground Control Points (GCPs) and Check Points (CPs), while extracted boundary coordinates were compared with provisional cadastral boundaries, cadastral surveying data, and field verification measurements to assess spatial consistency and boundary discrepancies. The results showed that the UAV-based 3D model generally satisfied the positional accuracy requirements for cadastral resurvey projects.

Most sample boundary points were within the legal tolerance of ±0.07 m, and the model demonstrated stable spatial consistency even in a complex urban environment. The 3D model also enabled effective analysis of boundary discrepancies associated with building protrusions, retaining walls, fences, and narrow alley structures that are difficult to interpret using conventional 2D orthophotos. The study confirmed that integrating UAV-derived 3D spatial information with boundary surveying data and provisional boundary plans can improve the interpretability of cadastral boundary verification and support decision-making during the cadastral resurvey process.

The results indicate that UAV-based 3D models can serve as practical tools for identifying spatial relationships and analyzing the causes of boundary inconsistencies. However, severe occlusion, shadows, and restricted visibility limited the complete reconstruction of some boundary features, indicating the need for complementary ground surveying and field verification. Overall, this study demonstrates that UAV photogrammetry-derived 3D models have practical applicability as supplementary spatial information for cadastral boundary verification and can contribute to improving the efficiency, interpretability, and spatial reliability of urban cadastral resurvey projects.

Keywords: UAV Photogrammetry, UAV-based 3D Model, Cadastral Resurvey Project, Boundary Verification, Urban Dense Area, Spatial Consistency, UAV Spatial Information