Atmospheric delay analysis from GPS and InSAR

In the paper we proposed a comparison methodology between GPS delay and SAR Atmospheric Phase Screen (APS) in both differential and pseudo-absolute mode. ENVISAT ASAR and synchronous GPS campaign data in Como, Italy were collected and processed. APS from PSInSAR has been divided into even groups according to their height for analysis of stratification sensitivity. Then the stratification and assumed turbulent terms from SAR APS and GPS were compared. The stratified ratio from GPS and SAR APS in differential mode is in agreement of 7.7 mm/km with bias of 3.4 mm/km, with a correlation coefficient higher than 0.7 in the ascending case. The atmospheric total delay coincides with STD of differences smaller than 4 mm (~0.65 mmPWV) with correlation coefficients higher than 0.6. The results predicted the extent on which atmospheric measurements from GPS and InSAR are comparable.