Ionospheric correction of SAR interferograms by multiple-aperture interferometry

Hyung Sup Jung, Dong Taek Lee, Zhong Lu, Joong Sun Won

Research output: Contribution to journalArticlepeer-review

80 Scopus citations


Interferometric synthetic aperture radar (InSAR) is a powerful technique that precisely measures surface deformations at a fine spatial resolution over a large area. However, the accuracy of this technique is sometimes compromised by ionospheric path delays on radar signals, particularly with L- and P-band SAR systems. To avoid ionospheric effects from being misinterpreted as ground displacement, it is necessary to detect and correct their contributions to interferograms. In this paper, we propose an efficient method for ionospheric measurement and correction and validate its theoretical and experimental performance. The proposed method exploits the linear relationship between the multiple-aperture interferometry phase and the azimuth derivative of the ionospheric phase. Theoretical analysis shows that a total electron content (TEC) accuracy of less than 1.0 × 10-4 TEC units can be achieved when more than 100 neighboring samples can be averaged (multilooked), and the coherence is 0.5. The regression analysis between the interferometric phase and the topographic height shows that the root-mean-square error can be improved by a factor of two after ionospheric correction. A 2-D Fourier spectral analysis indicates that the ionospheric wave pattern in the uncorrected power spectrum has disappeared in the power spectrum of the corrected interferogram. These results demonstrate that the proposed method can effectively remove ionospheric artifacts from an ionosphere-distorted InSAR image. Note that the method assumes that there is no appreciable surface displacement in the along-track dimension of the interferogram.

Original languageEnglish
Pages (from-to)3191-3199
Number of pages9
JournalIEEE Transactions on Geoscience and Remote Sensing
Issue number5
StatePublished - 2013


  • Advanced Land Observation Satellite (ALOS) Phased-Array-type L-band Synthetic Aperture Radar (PALSAR)
  • Interferometric synthetic aperture radar (InSAR)
  • Ionospheric correction
  • Ionospheric phase map
  • Multiple-aperture interferometry (MAI)
  • Synthetic aperture radar (SAR)


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