semiactive-guidance system

A semiactive guidance system is a type of missile guidance where the missile homes in on energy that is reflected off the target from a source other than the missile itself. This energy can be radar emissions or laser light.1

For example, the U.S. Hawk and Soviet SA-6 Gainful antiaircraft systems use semiactive radar guidance. The missile tracks radar signals transmitted from the launch site that bounce off the target. Similarly, laser-guided missiles use a seeker to lock onto a laser spot illuminating the target.1

This method differs from active guidance, where the missile generates its own emissions to track the target, and passive guidance, which relies on emissions from the target itself. Semiactive guidance allows for flexibility, as the source illuminating the target can be separate from the launch platform.21