Volume IV-2/W4
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 207-211, 2017
https://doi.org/10.5194/isprs-annals-IV-2-W4-207-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 207-211, 2017
https://doi.org/10.5194/isprs-annals-IV-2-W4-207-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.

  13 Sep 2017

13 Sep 2017

SRTM DEM-AIDED DEM EXTRACTION METHOD FOR ISLAND AND REEF

X. W. Chen1,2, C. Zhao1, H. T. Guo1, Y. Z. Lin1, and D. H. Yu1 X. W. Chen et al.
  • 1Zhengzhou Institute of Surveying and Mapping, Zhengzhou, China
  • 2Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China

Keywords: DEM Extraction, Island and Reef Image, SRTM DEM, Rational Function Model, Least Square Matching

Abstract. An SRTM DEM-aided DEM extraction method for island and reef is proposed to solve the problem of island and reef DEM extraction based on satellite imagery. The SRTM DEM is fully integrated into this method, namely, it is used to provide initial elevation for DEM and also to mark the sea area points in order to avoid the adverse effect of sea area image on DEM extraction. When determining elevations of grid points, only the valid land area points (VLPs) are taken into account. On the basis of initial elevation, the image coordinates of VLPs in multi-view images are determined and precise coordinates of conjugate points are obtained based on least square matching, then ground coordinates of VLPs are acquired by forward intersection. Finally, the elevations of VLPs are determined based on these object space points through data interpolation, and the sea area points are set as a uniform value. Experimental results show that the method can effectively solve the problem of island and reef DEM extraction. It can effectively extract DEM from island and reef satellite images regardless of the land area proportion, and island and reef can be completely extracted. Accuracy of the extracted DEM would improve with the increase of DEM resolution; when the resolution is relative high, the accuracy is consistent with SRTM DEM. The computational efficiency depends on the land area proportion and DEM resolution.