Modeling Atmospheric Effects of InSAR Measurements based on Meris and GPS observations

Atmospheric water vapor is a major limitation for high precision interferometric synthetic aperture radar (InSAR) applications due to its significant impact on microwave signals. Temporal variability of the atmosphere delay can be estimated directly from GPS data, but spatial variations of water-vapor-induced distortions cannot easily be separated by the sparse network of GPS observations in the imaged area. The primary objective of this work is to build a hybrid model combining the GPS and Medium Resolution Imaging Spectrometer (MERIS) water vapor measurements for correcting the atmosphere effects on InSAR measurements. Moreover, a comparison between MERIS and GPS water vapor products was performed using data covering Beijing from January 2004 to February 2007. MERIS water vapor values appeared to be slightly greater than GPS values. However, MERIS water vapor agreed well with GPS water vapor retrievals under Beijing's conditions with a RMS error of 2.38 mm.