Use of Multi-Squint InSAR to Separate Surface Deformation from Troposphere Delay

AbstractTropospheric delays can be the leading source of error in spaceborne interferometric Synthetic Aperture Radar (InSAR) measurements. Here, we find that the non-uniform troposphere delay features are dependent on the squint angles used for repeat pass InSAR. Large squint angles cause bigger along track shifts for these non-uniform trop-osphere delay features. Through processing the L-band UAVSAR data with 3 different squint angles, we were able to see the various non-uniform delay structures with different sizes and varying delays of up to a couple of centimeters throughout the observed in-terferograms. We were also able to estimate the altitude of the effective troposphere delay layers. The understanding of the squint dependent troposphere delay can help us sep-arate the surface deformation, which is also included in the InSAR phase measurements, from the atmosphere delays. A few methods are proposed for this separation. We used UAVSAR data and simulated surface deformations to verify these methods. This tech-nique can also be used to space-borne cases.