Noise jamming of a FM band commensal radar

Commensal Radars (CRs) are a class of EM sensor that use the emissions of other systems to fulfill their function, without having any impact or collaboration with the emitter of opportunity. The jamming of Commensal Radar (CR) systems, and possible ECCM responses to such jamming have not received more than a passing reference in the open literature. We examine a specific case of an FM Band Commensal radar with a multi-receiver configuration (single transmit site, many spatially distributed receivers) and find that although modest jammer power can be very effective in jamming the CR, the unknown geometry and frequencies of operation of the Commensal Radar (CR) will make it difficult to jam in practice. Simple null steering by the CR receivers is very effective. We also note that the CR system requires excellent Electronic Support Measures (ESM) to be aware of electronic attack. The paper reviews the tactical situation, and the very sparse literature. This is followed by some analysis of the effect of noise jamming, followed by simulations of jamming, with and without receiver null steering, as well as some self-protection jamming.