Results of Dual-Polarimetric Airborne Passive Radar

Polarimetry in remote sensing applications has emerged as a valuable technique for enhancing the information content of Synthetic Aperture Radar (SAR) images. Passive radar exploits existing illuminators of opportunity, e.g. broadcast or communication transmitters, for sensing applications, i.e. target detection or SAR imaging. Terrestrial broadcast transmitters emit the signal typically using only one linear polarization (horizontal or vertical). In this cases, full-polarimetry, as it is known from active remote sensing applications, is not usable for passive radar. However, if the receiver is equipped with dual-polarized antenna elements, dual-polarimetry techniques can be applied. It has the potential to improve the quality and interpretability of passive radar data. In this paper, we present results and analysis of dual-polarimetric passive SAR images. We calculate the coherence between horizontal and vertical polarized SAR images for two different scenes. Additionally, we calculate the Stokes parameter and derive a quantitative measure from the Stokes parameters to improve the interpretability of the SAR images.