Comparative assessment of GNSS- and GACOS-based tropospheric corrections for InSAR-derived surface deformation: a case study of the 2020 Elazığ–Sivrice earthquake
EARTH SCIENCE INFORMATICS, cilt.19, ss.1-24, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 19
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s12145-026-02236-1
- Dergi Adı: EARTH SCIENCE INFORMATICS
- Derginin Tarandığı İndeksler: Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Earth, Atmospheric, & Aquatic Science Collection (ProQuest), Scopus, Technology Collection (ProQuest), Aerospace Database, Science Citation Index Expanded (SCI-EXPANDED), Geobase, INSPEC
- Sayfa Sayıları: ss.1-24
- Erciyes Üniversitesi Adresli: Evet
Özet
The effect of Global Navigation Satellite System (GNSS)-based tropospheric corrections on Interferometric Synthetic Aperture Radar (InSAR)-derived surface deformation estimates was evaluated for the 24 January 2020 Mw 6.8 Elazığ Sivrice earthquake. Tropospheric delay is a major source of error in InSAR processing and may affect the interpretation of earthquake-induced deformation fields. To assess this effect, ascending and descending Sentinel-1A images were processed using the Sentinel Application Platform (SNAP) within a standard Differential InSAR (DInSAR) workflow. Phase filtering was applied to reduce noise, and phase unwrapping was performed using the Statistical-Cost, Network-Flow Algorithm for Phase Unwrapping (SNAPHU). Tropospheric delays estimated from GNSS observations were applied to the interfero metric displacement products and compared with corrections from the Generic Atmospheric Correction Online Service for InSAR (GACOS). The results show that both GNSS- and GACOS-based corrections influence the spatial distribution of line-of-sight (LOS) displacement fields. However, their effects are not spatially uniform across the study area. Local discrepancies between the corrected products are likely related to regional atmospheric variability, topography, acquisi tion geometry, and the distribution of GNSS stations. Neither correction strategy produced a spatially uniform improve ment across all interferometric pairs; instead, the results highlight the need to carefully evaluate atmospheric correction performance using spatial statistics, profile comparisons, and displacement-difference analyses. This study demonstrates that GNSS- and GACOS-based corrections do not uniformly improve displacement products but provide complementary information for identifying atmospheric contributions and assessing uncertainty in InSAR-derived earthquake deformation fields.