Human and drone surveillance via RpF-based WiFi passive radar. Experimental validation

This work deals with the short-range monitoring of small radar cross section targets using commercial WiFi transmitters as source of opportunity. Proper modifications to the conventional WiFi-based passive radar signal processing scheme are presented, based on the use of the Reciprocal Filter (RpF) approach for range compression, that (i) simplify the overall scheme (ii) make the processing robust to current and future IEEE 802.11 standards that might be characterized by mixed modulation transmissions (iii) result in a better sidelobe control (iv) enable an easier and cost-effective clutter cancellation strategy. Then, we introduce an appropriate solution to tackle the signal-to-noise ratio loss introduced by the presented strategy. The effectiveness of the resulting processing scheme is tested on experimental data, collected in both the 2.4 and 5 GHz WiFi bands, against both humans and a small drone.