On the Influence of the Atmosphere on Spaceborne - SAR System Calibration

Abstract

This contribution is concerned with the problem of identifying and estimating the influence of the atmosphere (troposphere and ionosphere) in the procedure of spaceborne SAR system calibration. As the operating frequencies are increasing the attenuation due to hydrometeors are becoming more relevant especially in the case of convective rain events. On the other hand, if lower frequencies such as L- band are applied, ionospheric propagation effects are possibly adding errors to polarimetric measurements due to a rotation of the polarization plane, well known as the Faraday rotation. First we will provide a brief review on atmospheric effects capable of influencing SAR measurements and how they could deteriorate the image quality. In a second step a discussion on the current status of the calibration strategy and activities in the context of propagation effects for TerraSAR-X, the new German Synthetic Aperture Radar remote sensing satellite, will be given.