The Missile Approach Warning System (MAWS) answers the question the RWR leaves open: is a missile actually coming at me? A SARH missile gives itself away indirectly through the CW illumination (Semi-Active Radar Homing), but a passive IR missile (Passive homing) — the main threat to helicopters and transport aircraft — emits nothing at all. The MAWS therefore does not detect the guidance but the missile itself.
Three sensor principles, each with its own strengths:
| Principle | Detects | Strength | Weakness |
|---|---|---|---|
| UV sensors | the UV radiation of the motor plume | hardly any false alarms (few natural UV sources in the background, Structure of the EMS) | only while the motor is burning; limited range |
| IR sensors (MWIR, Division of the infrared spectrum) | the hot plume and the aerodynamically heated missile | longer range; also sees the missile after motor burnout | warm, cluttered backgrounds → false-alarm management needed |
| Active (pulse-Doppler) radar | the approaching missile as a small, fast target (Pulse-Doppler radar and Moving Target Indicator) | the only one that measures range and closing speed → exact time to impact | transmits itself (signature!); small-RCS target (Radar Cross Section) |
Several sensors around the platform give spherical coverage. The processor distinguishes a real launch from sun glints, fires or fireworks (false alarm rejection — crucial: a system that cries wolf too often gets switched off), determines the direction of arrival and classifies: is the object approaching, and how fast?
After that, only speed counts — a MANPADS engagement lasts seconds. In modern installations the MAWS therefore automatically triggers:
- flare/chaff programmes matched to the threat direction (Characteristics);
- the DIRCM turret, which acquires and jams the missile's seeker on the MAWS bearing (Directional Infrared countermeasures);
- audio/visual cues for the crew, including manoeuvre advice.
RWR and MAWS are complementary and together complete: the RWR hears the radar chain progressing (search → track → guidance) and warns before the shot; the MAWS sees the shot itself — including the shot for which no radar was needed at all. Their fusion in the EW suite determines which layer of the package (manoeuvre, expendables, decoys, DIRCM, jamming) is used when.