Mazurek et al. Figure 11. Minimal configuration of four-channel RF signal acquisition system. A simplified version of the system without injection of pilot signals has been implemented and also tested in PCL application deployed on moving airborne platform (C-295M CASA aircraft [28]). This version employs calculation of cross correlation between the received signals to estimate and compensate the time delays, leaving unknown and uncompensated phase shifts. Figure 12. Receiving antenna array used in PCL experiments on navy ship. A very compact four-channel RF acquisition system can be implemented with two RSPduo devices and a host PC (e.g., Intel NUC [29] with Core i5-7260U CPU), as shown in Figure 11. If only two RF signals (i.e., surveillance and reference channel) are sufficient, even simpler configuration is possible, with just one RSPduo receiver and a host computer. Such a lightweight, low-power architecture suits Figure 13. Uncompensated phase delays and time shifts in signals from lightweight system. APRIL 2022 IEEE A&E SYSTEMS MAGAZINE 35