A key component in Missile Countermeasures Devices (MCD) and Active Protection Systems (APS) is the threat warning. The most mature system is the laser warning device.

VVR-2 produced by Goodrich, has been deployed with USMC LAV reconnaissance vehicles since 1996, and are currently being augmented by the more advanced VVR-3, which is capable of detecting laser rangefinders, designators as well as beam-riding missiles at a 360 degrees azimuth and 55 deg. elevation. A similar system developed by EFW, is the Threat Detection System (TDS) a multi-spectral system that can detect both laser and IR illuminators. Offering high accuracy, the system has an expanded coverage of 110 degrees in elevation and 360 degrees azimuth.