PS Point Selection Based on Phase Stability of Time Series Phase Unwrapping

In Time Series SAR interferometry (TS-InSAR) analysis, the screening results of permanent scatterers (PS points) affect the accuracy and efficiency of phase unwrapping of TS-InSAR. In the case of atmospheric effect and random noise, the traditional PS point screening method will lead to incomplete noise removal and loss of key deformation information points. To solve this problem, a phase stability PS point screening method based on the traditional method is proposed in this paper. By analyzing the influence of the noise residual phase on the interference vector distribution, this method proposes a formula for calculating the phase coherence coefficient of a long time series midpoint. By setting a reasonable threshold to screen the phase coherence of global points, PS points that are relatively stable in amplitude and phase can be obtained, and the efficiency of subsequent phase unwinding and the precision of processing results can be improved.