On polarimetric calibration for ultra wideband radar

Ultra wideband (UWB) radar is an emerging technology with potential for all-weather, remote sensing of objects obscured by foliage or buried underground. Multiple octaves of frequency coverage and 90 degrees or more of viewing angle across a synthesized aperture are used to obtain high spatial resolution mapping of scattering behavior. Additionally, fully polarimetric responses can be measured, providing a multichannel characterization of objects in a scene. However, the diversity in wavelength and viewing angle presents significant challenges for system engineering and data interpretation. In particular, the multichannel UWB system poses unique imaging challenges arising from the variation of the UWB antenna response. We present an overview of calibration techniques for polarimetric wideband imagery, and introduce an image domain calibration technique using calibration targets.