1. A radar system for detecting a presence of a ballistic projectile, comprising: a source of radio frequency energy, sited remotely from a target, for illuminating airspace around the target; a receiver, sited locally to the target, the receiver having first and second receiving channels, the first receiving channel configured to acquire a reference signal from the source, and the second receiving channel configured to acquire a second signal from the source, the second signal reflected by the projectile; and a signal processor including a means for determining whether the projectile poses an imminent threat to the target.