[1]SHI Yangzi,HUANG Tingting,LUO Jianyong,et al.Evaluation on the Accuracy of Structure From Motion(SfM)Photogrammetry on Gully Surveying[J].Research of Soil and Water Conservation,2020,27(01):39-46.
Copy
Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
27
Number of periods:
2020 01
Page number:
39-46
Column:
Public date:
2020-02-20
- Title:
-
Evaluation on the Accuracy of Structure From Motion(SfM)Photogrammetry on Gully Surveying
- Author(s):
-
SHI Yangzi1, HUANG Tingting1, LUO Jianyong1, YANG Yang1, LIU Baoyuan2
-
(1.State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; 2.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and ministry of Water Resources, Yangling, Shaanxi 712100, China)
-
- Keywords:
-
structure from motion(SfM)photogrammetry; gully survey; real-time kinematic(RTK)GPS; ground control point; digital elevation model(DEM)
- CLC:
-
S157.1
- DOI:
-
-
- Abstract:
-
A typical gully was selected and measured using the tape method and structure from motion(SfM)photogrammetry in the village of Liangjianfang, Luanping County, Hebei Province. The accuracies of both gully surveying methods were evaluated via comparing the results with those obtained by the real-time kinematic(RTK)GPS. In addition, different spatial distribution schemes of ground control points(GCPs)used in the SfM photogrammetry were designed and their impact on the gully measurement accuracy was assessed. The results show that SfM photogrammetry can serve as a highly accurate technique for gully surveying. Compared to RTK GPS, the tape method misestimates the gully volume by 37.28%, whereas the SfM photogrammetry overestimates the volume by only 2.40%, when the DEM obtained by RTK GPS is subtracted from the one by SfM photogrammetry, the resulting elevation difference falls between -0.2 m and 0.2 m for more than 70% of the pixels; moreover, the laser range finder(LRF)was demonstrated as an effective alternative for the determination of GCP coordinates; for each pair of GCPs, LRF generates statistically similar spatial distance and elevation difference with the classical RTK GPS; furthermore, the gully volume derived by SfM photogrammetry based on such GCP measurement is only misestimated by 0.23% compared to the volume obtained by RTK GPS. Reducing the number of GCPs on the gully edge and bottom from 18 to a range between 4 and 16, little difference is detected in the corresponding DEMs reconstructed by the SfM photogrammetry. Compared to the DEM grounded on all the 18 GCPs, the elevation difference is within the range between -0.05 and 0.05 m for most pixels, disregarding the number and locations of the GCPs considered. The estimation errors for gully volume, accordingly, are all smaller than 5%. These findings demonstrate that SfM photogrammetry has high precision in terms of gully measurement, and is applicable for rapid and accurate gully survey in the field, which has great practical implications for gully monitoring and gully erosion research.