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.