Methods for Atmospheric Correction in INSAR Data
Franz Meyer(1) , Bert Kampes(1)
, Richard Bamler(1)
, and Juergen Fischer(2)
German Aerospace Center (DLR),
(2) Free University Berlin, Carl-Heinrich-Becker-Weg 6-10, 12165 Berlin, Germany
Atmospheric effects are an important error source for correct interpretation of interferometric products. These effects and several methods for correcting them in SAR and in InSAR data are currently investigated in the framework of the ESA Cat. I project ACID (Atmospheric Correction of InSAR Data). For the application of Persistent Scatterer Interferometry (PSI), the benefit of Kriging Interpolation for separating atmospheric contributions from noise is analyzed in detail. The sensitivity to various tunable parameters is studied, for example the choice of variogram model, output grid size, and the ratio of noise and signal power. Moreover, the influence of outliers, e.g., local unwrapping errors, in the input data is studied.
Secondly, the use of MERIS data for mitigating atmospheric influences in interferometric ENVISAT data is investigated. This includes a theoretical analysis of the potential of MERIS data for correcting atmospheric effects in InSAR data based on error propagation, and an analysis of the severity of atmospheric influence for a variety of viewing angles. The latter analysis is extended to PSI to reach a better understanding of the nature of the PS points, and in order to define an optimal sensor configuration for future missions.