Özet
This investigation evaluates the performance of digital terrain models (DTMs) generated in different vertical datums by aerial LiDAR and unmanned aerial vehicle (UAV) photogrammetry techniques, for the determination and validation of local geoid models. Many engineering projects require the point heights referring to a physical surface, i.e., geoid, rather than an ellipsoid. When a high-accuracy local geoid model is available in the study area, the physical heights are practically obtained with the transformation of global navigation satellite system (GNSS) ellipsoidal heights of the points. Besides the commonly used geodetic methods, this study introduces a novel approach for the determination and validation of the local geoid surface models using photogrammetry. The numeric tests were carried out in the Bergama region, in the west of Turkey. Using direct georeferenced airborne LiDAR and indirect georeferenced UAV photogrammetry-derived point clouds, DTMs were generated in ellipsoidal and geoidal vertical datums, respectively. After this, the local geoid models were calculated as differences between the generated DTMs. Generated local geoid models in the grid and pointwise formats were tested and compared with the regional gravimetric geoid model (TG03) and a high-resolution global geoid model (EIGEN6C4), respectively. In conclusion, the applied approach provided sufficient performance for modeling and validating the geoid heights with centimeter-level accuracy.
| Orijinal dil | İngilizce |
|---|---|
| Makale numarası | 524 |
| Dergi | ISPRS International Journal of Geo-Information |
| Hacim | 9 |
| Basın numarası | 9 |
| DOI'lar | |
| Yayın durumu | Yayınlandı - Eyl 2020 |
Bibliyografik not
Publisher Copyright:© 2020 by the authors.
Finansman
This research was carried out as part of the second author's graduate thesis study (Council of Higher Education database no. 510451), which was prepared and successfully defended at Istanbul Technical University, Graduate School of Science Engineering and Technology. Part of the provided results in this article was presented by the authors in Turkish as a poster in 17th National Map and Cadastral Scientific and Technical Congress in April 2019. The airborne LiDAR data were provided by the general directorate of mapping and UAV data were provided by the General Directorate of geographic information systems of Turkey. DTM generation were carried out using Envi LiDAR and Global Mapper GIS Software. The point cloud data were prepared for DTM generation using CloudCompare Software. In statistical evaluation of the products, Surfer Golden Software was used. Global geopotential model was obtained from International Center for Global Earth Models (ICGEM) database. The authors acknowledge the editors and three anonymous reviewers for their valuable comments that significantly improved the quality of the manuscript.
| Finansörler | Finansör numarası |
|---|---|
| Graduate School of Science Engineering and Technology | |
| Istanbul Teknik Üniversitesi |
BM SKH
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