Exploring the generation of digital elevation models from same-side ERS SAR images: Topographic and temporal effects

Zhilin Li, Guoxiang Liu, Xiaoli Ding

Research output: Journal article publicationJournal articleAcademic researchpeer-review

12 Citations (Scopus)

Abstract

This paper presents an attempt to explore the generation of digital elevation models (DEMs) by radargrammetry from same-side ERS-1/2 synthetic aperture radar (SAR) images. Two ERS-1 and two ERS-2 C-band (wavelength 5·6 cm) SAR images along parallel descending orbits, acquired in 1996 and 1997, are used to form four stereopairs. The test area is western Hong Kong which is dominated by mountains/hills that are largely covered by evergreen-broadleaf trees. The stereopairs covering the same area but with different time intervals (varying from 16 days to 1·5 years) have an intersection angle of 45 and a relatively small overlap of 30%(30 km). In addition to the effect of topography, the effect of temporal correlation on the accuracy of the resulting DEMs is also analysed for the first time. From the experimental results obtained in this study, the following conclusions may be drawn: (a) with sameside ERS-1/2 SAR images, an accuracy of 30 to 35 m is achievable; (b) the accuracy of a resulting DEM degrades almost linearly with an increase in slope when the terrain slope is below 30, and in the areas with slope over 30, the accuracy of the DEM is significantly degraded and even becomes unacceptable; (c) the worst accuracy is obtained in the foreslope directions and the best accuracy is obtained in the backslope directions; (d) the time interval between two SAR images has no significant effect on the accuracy of the DEM in general; (e) the time interval between two SAR images has no significant effect on the reliability of image matching. Journal Compilation
Original languageEnglish
Pages (from-to)124-140
Number of pages17
JournalPhotogrammetric Record
Volume21
Issue number114
DOIs
Publication statusPublished - 1 Jun 2006

Keywords

  • Accuracy assessment
  • DEM
  • ERS SAR images
  • Radargrammetry
  • Temporal correlation
  • Topographic dependency

ASJC Scopus subject areas

  • Engineering (miscellaneous)
  • Computer Science Applications
  • Computers in Earth Sciences
  • Earth and Planetary Sciences (miscellaneous)

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