Preliminary experimental results for a multi-channel forward scatter radar

This paper reports preliminary experimental tests for a multi-channel Forward Scatter Radar (FSR), namely a FSR system equipped with multiple receiving channels connected to closely spaced antennas. While the majority of the technical literature on FSR focuses on single-channel FSR and exploits signal processing schemes operating in time domain, multichannel FSR has been recently shown to allow target detection and direction of arrival (DoA) estimation by exploiting the signal amplitude modulation that the target induces across multiple antenna elements. Specifically, the theoretical investigations have suggested the use of simple amplitude-based spatial processing schemes to extract the target signature, with tremendous advantages in terms of system complexity. This study aims to validate the theoretical framework by preliminarily demonstrating the practical feasibility of a multi-channel FSR in real-world conditions, with particular reference to an integrated sensing and communication (ISAC) scenario. To this purpose, software-defined radios (SDRs) and commercial antennas are employed to transmit orthogonal frequency division multiplexing (OFDM) signals in S band and several tests are performed with different cooperative targets (e.g., people, drones) moving in the area between the transmitter and the multi-channel receiver. This experimental setup not only provides a first proof of concept for the proposed multi-channel FSR but also enables a preliminary performance comparison between the amplitude-based spatial processing approach and the conventional single-channel FSR that implements time domain processing.