Evaluation of Tidal Effect in Long-Strip DInSAR Measurements Based on GPS Network and Tidal Models

A long-strip differential interferometric synthetic aperture radar (DInSAR) measurement based on multi-frame image mosaicking is currently the realizable approach to measure large-scale ground deformation. As spatial range of mosaicked images increases, nonlinear variation ocean tidal loading (OTL) displacements more significant, and using plane fitting remove errors will produce large displacement residuals in a region with complex coastline. To conveniently evaluate effect mosaic DInSAR interferograms along west coast U.S., three-dimensional OTL grid generated by integrating constituents’ estimation GPS reference station network global/regional models. Meanwhile, solid earth tide (SET) model IERS conventions used estimate high-precision SET displacements. Experimental results show that interferogram can reach 77.5 mm, which corresponds 19.3% component. Furthermore, traditional bilinear ramp methods cause 7.2~20.3 mm residual interferograms, integrated constituents calculation method accurately eliminate tendency interferograms.