Correction of DInSAR noise using GNSS measurements

Differential SAR interferograms map the ground displacements with high spatial resolution. Many signals of interest, for example, those due to earthquakes and volcanic activities, are spatially correlated and are often obscured by artifacts caused by tropospheric and ionospheric fluctuations, inaccurate orbit data, and errors in the digital elevation model. In this study, a method to correct for such spatially-correlated noise in differential SAR interferograms is proposed. This method relies on a general fact that the displacements measured with the global navigation satellite systems are accurate enough. The proposed method is applied to a data set composed of long-strip (∼230 km) SAR images acquired by ALOS/PALSAR in Kinki region, Japan. It is shown that long-wavelength noise is successfully suppressed, which enables us to discuss short-wavelength features that were hidden in the original interferograms.