Correcting atmospheric effects in ASAR interferogram with MERIS integrated water vapor data

The troposphere delay of radar signals has been one of the major limitations for the application of high precision repeat pass InSAR. In this paper, we present the atmospheric correction methods for ASAR interferograms with MERIS integrated water vapor (IWV) data. Then, using four ASAR interferometric pairs over Southern California as examples, this paper conducts the atmospheric corrections with MERIS IWV data. The results show that after the correction the RMS differences between InSAR and GPS were reduced by 41. 7%, 65. 2%, 19.3%, and 39. 4%, respectively for the four selected interferograms, with an average improvement of 41. 4%. Most importantly, after the correction, three distinct deformation areas have been identified, i. e. , Long Beach-Santa Ana Basin, Pomona-Ontario and San Bernardino, with the deformation velocities ranging from -8 mm/a to -28 mm/a and on average around - 20 mm/a. The deformation is quite consistent with the historical deformation derived by other researchers. Thus, using the cloudless MERIS IWV data for correcting the synchronized ASAR interferogram can significantly reduce the atmospheric effects in the interferograms and further better capture the ground deformation and other geophysical signals.