Tropospheric Correction using PyAPS in the West Region of Venezuela
Geofisica Internacional, cilt.65, sa.3, ss.2339-2355, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 65 Sayı: 3
- Basım Tarihi: 2026
- Doi Numarası: 10.22201/igeof.2954436xe.2026.65.3.1930
- Dergi Adı: Geofisica Internacional
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Geobase, Directory of Open Access Journals, DIALNET
- Sayfa Sayıları: ss.2339-2355
- Anahtar Kelimeler: COLM, Displacement, InSAR, Subsidence, Venezuela
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Atatürk Üniversitesi Adresli: Evet
Özet
The subsidence of the East Coast of Lake Maracaibo-COLM in Zulia state in Venezuela is a geological event of anthropic cause with almost a century of existence. We wanted to know the current state of this event with the use of the Interferometric Synthetic Aperture Radar-InSAR technique, for this, we emphasized the need to mitigate atmospheric delays in the data, for which the ERA5 climate model with PyAPS was applied. In order to obtain accurate subsidence measurements in three oil fields located in the COLM (Tia Juana, Lagunillas and Bachaquero), whose cumulative subsidence process is approximately 5 meters between 1926 and 1986. For this study, subsidence values were estimated, for the period from 2018 to 2020, using a dataset of 157 interferometric Sentinel-1 images (79 from ascending orbits and 78 from descending orbits), which allowed the calculation of the values of displacements along the line of sight-LOS for both orbits, the tropospheric delay contribution, and the east-west and vertical components values, extracted from representative pixels with high coherence and with spatial and temporal average, having random noise component reduced, obtaining displacement values for Tia Juana, Lagunillas and Bachaquero fields respectively of: -6.4 +/- 0.8 cm/y; -7.9 +/- 1.0 cm/y and; -7.1 +/- 0.8 cm/y, for ascending mode. From 1.2 +/- 0.5 cm/y; -4.1 +/- 0.5 cm/y and; -1.8 +/- 0.3 cm/y, for descending mode. Also, by selecting representative pixels, we estimated reliable values for contribution from tropospheric delay, obtaining: -0.2 cm/y and -0.6 cm/y; -0.3 cm/y and -0.5 cm/y and; -0.4 cm/y and -0.5 cm/y. And the east-west (dE) and vertical (dU) components for the three fields, with: -6.79 cm/y and -2.94 cm/y; -3.27 cm/y and -5.19 cm/y and; -5.92 cm/y and -6.29 cm/y respectively, minimizing the risk that geometric projection errors will amplify underlying noise.