Passive GNSS-based SAR imaging and opportunities using Galileo E5 signals

This paper investigates the feasibility of Galileo navigation satellites as transmitters of opportunity in passive bistatic synthetic aperture radar （SAR） systems from the perspectives of signal processing and experiment program. Experimental images obtained using a single Galileo channel, E5a or ESb, are presented and analyzed. The paper also puts forward the channel combination scheme to jointly process E5a and E5b channels, which brings up high-resolution possibilities for passive SAR technique. By employing the entire E5 band for imaging, the range resolution may be potentially increased by up to 5 times. Preliminary experimental results for this concept are demonstrated.