Permafrost Dynamics Observatory—Part I: Postprocessing and Calibration Methods of UAVSAR L‐Band InSAR Data for Seasonal Subsidence Estimation

• Published in: Earth and space science (Hoboken, N.J.) N.J.), 2021-07, Vol.8 (7), p.e2020EA001630-n/a
• Main Authors: Michaelides, Roger J., Chen, Richard H., Zhao, Yuhuan, Schaefer, Kevin, Parsekian, Andrew D., Sullivan, Taylor, Moghaddam, Mahta, Zebker, Howard A., Liu, Lin, Xu, Xingyu, Chen, Jingyi
• Format: Article
• Language: English
• Subjects: Active Layer; active layer thickness; Algorithms; Arctic and boreal; Arctic zone; Asteroids; Biogeosciences; Calibration; Carbon; Comets; Comets: Dust Tails and Trails; Continental Crust; Cryobiology; Cryosphere; Earthquake Dynamics; Earthquake Interaction, Forecasting, and Prediction; Earthquake Source Observations; Estimation and Forecasting; Exploration Geophysics; Forecasting; Geodesy and Gravity; Gravity anomalies and Earth structure; Gravity Methods; Hydrology; Informatics; InSAR; Interferometry; Ionosphere; Ionospheric Physics; Magnetospheric Physics; Mathematical Geophysics; Monitoring, Forecasting, Prediction; Natural Hazards; Noise; Observatories; Ocean Predictability and Prediction; Oceanography: General; Other; Permafrost; Permafrost, Cryosphere, and High‐latitude Processes; Physical properties; Planetary Sciences: Comets and Small Bodies; Planetary Sciences: Solar System Objects; Polar environments; Policy; Policy Sciences; Prediction; Probabilistic Forecasting; Radar; Radio Science; Random variables; Remote Sensing; Results from 10 Years of UAVSAR Observations; Satellite Geodesy: Results; Seismic Cycle Related Deformations; Seismicity and Tectonics; Seismology; Space Weather; Subduction Zones; synthetic aperture radar; Tectonic Deformation; Time Variable Gravity; Transient Deformation; UAVSAR
• ISSN: 2333-5084; 2333-5084
• DOI: 10.1029/2020EA001630

Interferometric synthetic aperture radar (InSAR) has been used to quantify a range of surface and near surface physical properties in permafrost landscapes. Most previous InSAR studies have utilized spaceborne InSAR platforms, but InSAR datasets over permafrost landscapes collected from airborne platforms have been steadily growing in recent years. Most existing algorithms dedicated toward retrieval of permafrost physical properties were originally developed for spaceborne InSAR platforms. In this study, which is the first in a two part series, we introduce a series of calibration techniques developed to apply a novel joint retrieval algorithm for permafrost active layer thickness retrieval to an airborne InSAR dataset acquired in 2017 by NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar over Alaska and Western Canada. We demonstrate how InSAR measurement uncertainties are mitigated by these calibration methods and quantify remaining measurement uncertainties with a novel method of modeling interferometric phase uncertainty using a Gaussian mixture model. Finally, we discuss the impact of native SAR resolution on InSAR measurements, the limitation of using few interferograms per retrieval, and the implications of our findings for cross‐comparison of airborne and spaceborne InSAR datasets acquired over Arctic regions underlain by permafrost. Key Points We develop and present several calibration and postprocessing methods for seasonal subsidence estimation from interferometric synthetic aperture radar deformation Novel methods for phase referencing and uncertainty quantification due to nonergodicity within the multilook window are proposed Residual sources of uncertainty in active layer thickness estimation are discussed and quantified