Improving Obstacles’ Low Observability Using Multistatic RCS: Case of OHW Detection in OCAS for Flying Vehicles

Improving obstacles’ low observability is critical in radar system performance. This study concluded that, when applied to overhead wire (OHW) detection in obstacle collision avoidance system (OCAS) for flying vehicles (FVs), multistatic radar cross section (RCS) from a multi-input multi-output (MIMO) radar system seems to be a way to achieve that goal. Monostatic and multistatic RCSs are derived, highlighting the advantages of multistatic RCS. A complex envelope of signals received at individual antenna active elements as a function of aspect angle is determined from a multistatic RCS scenario. The stretch processing for complex range profiles from signals received by a radar after illuminating a target is examined. The 2-D range aspect angle intensity (RAAI) maps based on stretch processing using monostatic and multistatic RCS of perfect electric conductor (PEC) OHW and circular cylinder (CC) cable obstacles are generated. Multistatic RCS improvements relative to the normal incidence are in the order of 1.5, 6, and 7 dB for the PEC CC cable physical optics (P.O.) theoretical model, the Feko PEC twisted wire, and the Feko PEC CC cable, respectively. Multistatic RCS exhibits superior signal-to-noise ratio (SNR) detection differential over all aspect angles, in the order greater than 18 dB for simulation cases, and in the order of 15 dB for experimental cases analyzed in this study; hence, the multistatic RCS is more suitable for low observable obstacles’ detection, e.g., the detection of OHW obstacles for FVs’ OCAS. Detection behavior from both our experimental measurement collections using a TIDEP-01012 radar and simulation results agree.