A bi-static continuous wave radar system and related methods for detecting incoming threats from ballistic projectiles includes a remote source of RF illumination, and a local
receiver installed in one or more target aircraft. A first receiving channel acquires
direct path illumination from the source and provides a reference
signal, and a second receiving channel acquires a scatter
signal reflected by a
projectile. A processor coupled to each
receiver corrects scatter
signal Doppler offset induced by relative source motion, isolates
narrowband Doppler signals to derive signatures characteristic of the
projectile, and by executing appropriate algorithms, compares the derived signatures to modeled signatures stored in memory. If the comparison yields a substantial similarity, the processor outputs a warning signal sufficient to initiate defensive countermeasures.