DEM error correction in InSAR time series

Heresh Fattahi, Falk Amelung

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

We present a mathematical formulation for the phase due to the errors in digital elevation models (DEMs) in synthetic aperture radar (SAR) interferometry (InSAR) time series obtained by the small baseline (SB) or the small baseline subset method. We show that the effect of the DEM error in the estimated displacement is proportional to the perpendicular baseline history of the set of SAR acquisitions. This effect at a given epoch is proportional to the perpendicular baseline between the SAR acquisition at that epoch and the reference acquisition. Therefore, the DEM error can significantly affect the time-series results even if SB interferograms are used. We propose a new method for DEM error correction of InSAR time series, which operates in the time domain after inversion of the network of interferograms for the displacement time series. This is in contrast to the method of Berardino (2002) in which the DEM error is estimated in the interferogram domain. We show the effectiveness of this method using simulated InSAR data. We apply the new method to Fernandina volcano in the Galapagos Islands and show that the proposed DEM error correction improves the estimated displacement significantly.

Original languageEnglish (US)
Article number6423275
Pages (from-to)4249-4259
Number of pages11
JournalIEEE Transactions on Geoscience and Remote Sensing
Volume51
Issue number7
DOIs
StatePublished - Feb 1 2013

Keywords

  • Baseline history
  • digital elevation model (DEM) error
  • synthetic aperture radar (SAR) interferometry (InSAR)
  • time series

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Earth and Planetary Sciences(all)

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