InSAR Tropospheric Stratification Delays: Correction Using a Small Baseline Approach

Interferometric synthetic aperture radar (SAR) (InSAR) phase is affected by atmospheric path delay. It is common to separate the path delay into one component related to turbulent mixing processes and one component related to tropospheric stratification. Tropospheric stratification introduces phase delays correlating with topography, limiting interpretation of InSAR data in areas with steep topography. Improved access to SAR time series has led to the development of several innovative multitemporal InSAR algorithms. Small baseline (SB) is one such time-series method, based on combining and inverting a set of unwrapped interferograms to estimate surface displacement. In this letter, we present a method for estimating and correcting the effects of tropospheric stratification observed in an SB stack of interferograms. We demonstrate the value of this approach using InSAR data from the Envisat spacecraft and compare the InSAR estimated delays with results from a Global Positioning System network.