Article ID: 2020COL0013
In this report, we show the critical condition of the slope angle between orbits in InSAR (interferometric synthetic aperture radar) analysis. InSAR analysis, where the phase difference between two SAR observation data is measured, has been used for terrain height monitoring, and ground deformation detection, for example. However, InSAR data observed from nonparallel orbits degrades the performance of analysis. In the case of repeat-pass InSAR using airborne SAR, it is difficult to realize sufficiently parallel orbits. The purpose of this report is to formulate the nonparallel component of repeat-pass InSAR using an airborne SAR system and clarify the limitation of its parallel assumption. Then, we show the critical slope angle for use in InSAR analysis.