Assessment of Mitigation Strategies for Tropospheric Phase Contributions to InSAR Time-Series Datasets over Two Nicaraguan Volcanoes

Interferometric Synthetic Aperture Radar (InSAR) studies of ground displacement are often plagued by tropospheric artifacts, which are phase delays resulting from spatiotemporal variations in the refractivity of air within the troposphere. In this study, we focus on COSMO-SkyMed (X-band) InSAR products obtained over two different types of volcanoes in Nicaragua: the Telica stratovolcano and the Masaya caldera. We examine the applicability of an empirical linear correction method and three Global Weather Models (GWMs) with different spatial and temporal resolutions for removing the tropospheric phase component. We linearly invert the tropospheric-corrected interferograms using the Small BAseline Subset (SBAS) time-series technique to produce time-series of ground displacement. Statistical assessments were performed on the corrected interferograms to examine the significance of the applied corrections on the individual interferograms and time-series results. We find that the applicability of the correction methods is highly case-dependent and that in general, the temporal resolution of GWMs influences their ability to capture turbulent tropospheric phase delays. At the two target volcanoes, our study shows that none of the GWMs are able to accurately capture the tropospheric phase delays. Our study provides a guide for researchers using InSAR data in tropical regions who wish to use tropospheric model corrections to carefully assess the applicability of the different types of tropospheric correction methods.

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Work Title Assessment of Mitigation Strategies for Tropospheric Phase Contributions to InSAR Time-Series Datasets over Two Nicaraguan Volcanoes
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Open Access
Creators Kirsten J. Stephens; Christelle Wauthier; Machel Higgins; Peter La Femina
Version number 3
Keyword time-series analysis; tropical region; Nicaragua; InSAR; volcano; global weather models; tropospheric effects
License Attribution 4.0 International (CC BY 4.0)
Work Type Article
Publisher Remote Sensing
Publication Date February 26, 2020
Publisher Identifier (DOI) https://doi.org/10.3390/rs12050782
Deposited November 02, 2020 07:54

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Version 1
published

  • Created
  • Added Christelle_Wauthier-Assessment_of_mitigation_strategies-manuscript-v6-1.pdf
  • Added Creator Christelle Wauthier
  • Added Creator Machel Higgins
  • Added Creator Peter C. LaFemina
  • Published

Version 2
published

  • Created
  • Deleted Creator Peter C. LaFemina
  • Added Creator Kirsten J. Stephens
  • Updated Creator Christelle Wauthier
  • Updated Creator Machel Higgins
  • Added Creator Peter La Femina
  • Added remotesensing-12-00782-v2.pdf
  • Published

Version 3
published

  • Created
  • Deleted Christelle_Wauthier-Assessment_of_mitigation_strategies-manuscript-v6-1.pdf
  • Published