Simultaneous Observations of X-band Polarimetric SAR and Ground-based Weather Radar During a Tropical Storm to Characterize the Propagation Effects

Abstract:
Synthetic Aperture Radar (SAR) is a well established surface imaging technology with recent launches of SAR systems at smaller wavelengths for increased resolution observations. However, these higher frequency systems have to deal with the impact of precipitation modifying the observations. In particular, the X-band, multi-polarization TerraSAR-X launched by German Aerospace Center (DLR) in 2007 has acquired data with distinct storm signatures in the resulting images. These signatures usually appear as dark cloud-like features and occasionally are brighter on the near range side if significant backscatter from the melting layer is received. The dark feature is due to attenuation as the electromagnetic wave passes through the heavy precipitation and can have a polarization dependent effect. Together with ground based weather radar, the attenuation due to the storm can be further studied and quantified. This paper presents results from a storm case over Florida, USA from dual-polarization TerraSAR-X with simultaneous observations from a National Weather Service WSR-88D radar during a cyclone. In addition, since the primary SAR data is from surface backscatter which can change for a variety of reasons, images acquired 11 days prior to and after the storm are used to provide additional insight into the propagation component.