On the COSMO-SkyMed PingPong Mode to Observe Metallic Targets at Sea

A dual-polarimetric model to exploit X-band COSMO-SkyMed (CSK) dual-polarimetric PingPong mode synthetic aperture radar (SAR) data for metallic target observation purposes is first developed. The model relates the correlation between the copolarized channels, in case of sea surface with and without metallic targets, to the time offset between bursts related to the HH and VV polarimetric channels. Following this theoretical rationale, a constant false alarm rate (CFAR) approach is implemented to first exploit CSK PingPong full-resolution SAR data for target observation purposes. Experiments undertaken over a large data set of COSMO-SkyMed single look complex slant (SCS) PingPong HH/VV SAR data demonstrate the physical soundness of the approach and its effectiveness from an operational viewpoint. A whole CSK SAR scene is processed in about 10 s. Furthermore, the dual-polarization approach is also compared with a conventional single-polarization CFAR one and it is shown to perform best.