Revising digital elevation models generation from Sentinel-1 synthetic aperture radar and interferometric technique in densely-vegetated humid tropical environment

Abstract

Generation of digital elevation models (DEM) over densely vegetated humid tropics using Sentinel-1 data and Interferometry synthetic aperture radar (InSAR) technique is revised based on recommended optimum perpendicular baselines, and accuracy assessment based on coherence cells is introduced. Six pairs of Sentinel-1 data within the optimum perpendicular baseline of 150 − 400 m and different temporal baselines acquired between 2015 and 2021 were processed using Sentinel Application Platform. Results revealed: that due to the extreme difficulty of achieving good coherence, interferograms are characterized by noise, generated DEMs are dominated by artefacts, higher elevation accuracy can be achieved within coherence cells, and within the recommended optimum perpendicular baseline range, elevation accuracy within coherence cells is mainly determined by the perpendicular baseline compared to temporal baseline. Therefore, this study can provide practical guide for InSAR generated DEMs evaluation in densely vegetated environments, and remote sensing method for regional-scale measurement and mapping of spots heights.

Keywords:

• InSAR
• DEM
• coherence cells
• perpendicular baseline
• temporal baseline

Authors contributions

M.M. Chindo: PhD Candidate, Data Processing, Draft Writing, and Editing. M. Hashim: Conceptualization, Funding Acquisition, Supervision, Reviewing, Editing, and Writing. A.W. Rasib: Co-Supervision, Reviewing and Editing.

Acknowledgment

The authors acknowledge the satellite data provider: European Space Agency, particularly for their open access to Sentinel-1 SAR data.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We would like to thank Malaysia Research University Network grant (R.J130000.7809.4L881 and R.J130000.7809.4L882), Ministry of Higher Education, Malaysia and UTM High Impact Research grant (Q.J130000.2409.08G97), Universiti Teknologi Malaysia for providing the funds and facilities for carrying out the research.