Go Extra Miles: An Additional Error Correction Procedure Aimed to
Further Improve Phase Unwrapping Accuracy and Reduce Creep Model
Uncertainty
Abstract
Interferometric Synthetic Aperture Radar (InSAR) phase unwrapping error
is a major limiting factor on the InSAR-derived tectonic deformation
velocity. This is particularly the case when atmospheric turbulence,
large deformation gradient and strong phase noise exist. To address
limitations of existing phase unwrapping error correction methods which
are not supported for multi-looked InSAR data, here we present a new
algorithm that integrates decorrelation phase correction, triplet phase
closure (TPC) test and integer linear programming (ILP) to overcome this
limit. The rationale behind is that we mitigate the phase inconsistence
using decorrelation correction and then detect the phase unwrapping
error magnitude using TPC. Next we borrow the ILP from Compressed
Sensing that converts the phase unwrapping error correction to a sparse
signal recovery problem. We demonstrated the validity of our method by
using synthetic data and 5-years Sentinel-1 real data covering the
Central San Andreas Fault creep section, where exists obvious tectonic
deformation, strong atmospheric disturbance and decorrelated scatterers,
and the inverted long-term creep model constrained by InSAR velocity
after correction shows a lower uncertainty than that constrained by the
uncorrected one.