ABSTRACT
The standard implementation of full polarimetric SAR (PolSAR) involves the coherent transmission and reception of both vertically (V) and horizontally (H) polarized radar pulses. The PolSAR systems extract the complete polarimetric scattering information from a target scene but suffer from an increase in the pulse repetition frequency by a factor of two and an increase in the data rate by a factor of four over single polarization systems (Raney 2007). Nonetheless several partially polarimetric SAR systems have been proposed and there has been growing interest in dual-pol systems that transmit one polarization (e.g., linear horizontal or circular) and receive two polarizations (Dubois et al. 2008).A dual-pol system has advantage over a full polarimetric system in terms of reductions of pulse repetition frequency, data volume, and system power needs. However, dual-pol SAR systems do not acquire complete information pertaining to the full polarization state of the target. Souyris et al. (2005) proposed aDPmode called compact polarimetry (CP), where the system transmits only one polarization, either H + V (π/4 mode) or circular (right or left circular, RC or LC). They introduced a radar scattering model that assumes reflection symmetry and a relationship between the linear coherence and the cross-polarization (cross-pol) ratio.
