Effects of phase error on the relative height accuracy in interferometric synthetic aperture radar

To investigate the variation of relative height accuracy measured by InSAR system, how the phase error impacts on the relative height accuracy is analyzed on the basis of InSAR elevation measurement principle. The factors, which affect phase error, are researched in detail, such as signal to noise ratio, volume scattering, and temporal decorrelation, etc. Above methods has been used to analyze the relative height accuracy for spaceborne InSAR system with different wave bands. The results show that, under the condition of short wave length and fixed baseline, there is a look downwards angle that would optimize the relative height accuracy. Further, the numerical simulation has verified the existence of optimum look-down angle. The method and conclusions presented in this article are helpful for parameter design and performance analysis of InSAR system.