Interferometric coherence analysis with high resolution space-borne synthetic aperture radar

Sang Hoon Hong, Shimon Wdowinski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Recently high spatial resolution space-borne synthetic aperture radar (SAR) systems with various polarizations have launched and have operated successfully. Interferometric SAR (InSAR) processing with the high resolution space-based observations acquired by these systems can provide more detail information for various geodetic applications [1-5]. Coherence is regarded as a critical parameter in the evaluating the quality of an InSAR pair. In this study, we evaluate the coherence characteristics of high-resolution data acquired by TerraSAR-X (X-band) and ALOS (L-band) and intermediate-resolution data acquired by Envisat (C-band) over western Texas, U.S.A. Our coherence analysis reveals that the high-resolution X-band TSX (3.1 cm) data has a high coherence level (0.3-0.6), similar to that of the L-band ALOS data (23.5 cm) in short temporal baselines (Fig. 1). Furthermore, the TSX coherence values are significantly higher than those of the C-band (5.6 cm) Envisat data (Fig. 1). The higher coherence of the TSX dataset is a surprising result, because common scattering theories suggest that the longer wavelength SAR data maintain better coherence. In vegetated areas the shorter wavelength radar pulse interacts mostly with upper sections of the vegetation and, hence, does not provide good correlation over time in InSAR pairs. Thus, we suggest that the higher coherence values of the TSX data reflect the data's high-resolution, in which stable and coherent scatterers are better maintained. Although, however, the TSX data show a very good coherence with short temporal baseline (11-33 days), the coherences are significantly degraded as the temporal baselines are increased (Fig. 2). This result confirms previous studies showing that the coherence has a strong dependency on the temporal baseline [1-2]. We will continue this preliminary study by conducting additional coherence analyses over various environments and develop appropriate relationship that will account for data resolution in the coherence calculations.

Original languageEnglish (US)
Title of host publication2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011
Pages485-486
Number of pages2
StatePublished - 2011
Event2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011 - Seoul, Korea, Republic of
Duration: Sep 26 2011Sep 30 2011

Other

Other2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011
CountryKorea, Republic of
CitySeoul
Period9/26/119/30/11

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Keywords

  • coherence
  • high resolution satellite SAR
  • Interferometric SAR (InSAR)
  • temporal decorrelation
  • wavelength

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Communication

Cite this

Hong, S. H., & Wdowinski, S. (2011). Interferometric coherence analysis with high resolution space-borne synthetic aperture radar. In 2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011 (pp. 485-486). [6087088]