A Direct Method to Estimate Atmospheric Phase Delay for Insar with Global Atmospheric Models

Abstract

Differential Interferometric Synthetic Aperture Radar (DIn-SAR), also known as Persistent Scatters Interferometry (PSI), has proved its unprecedented advantages of monitoring ground deformation on large scale with centimeter to millimeter precision in the last two decades. However, the reliability and accuracy are often contaminated with atmospheric artefacts caused by spatial and temporal variations of the atmosphere. Recent studies revealed atmospheric artefacts can be compensated with empirical models, GPS zenith path delay and numerical weather prediction models. In this paper, an improved methodology is proposed based on atmospheric reanalysis data to estimate atmospheric artefacts. With our approach, the realistic line of sight (LOS) path along satellite location and monitored points is considered, rather than the zenith path delay. The effectiveness of our method is validated over Tenerife island, Spain by using Sentinel 1 datasets.