Combining passive and active radars

Recent conflicts have demonstrated how drones are used to find and destroy key assets with devastating effects. Ground-based air defence (GBAD) has proven to be particularly vulnerable due to its high power transmission, as loitering munition can detect and attack any source of power transmission.

This situation calls for an innovative protection solution – which HENSOLDT is offering with TwinSens. This powerful solution combines active and passive radar technologies and creates powerful synergies and decisive benefits for the operators.

Areas of operation

  • Ground-based air defence
  • Air surveillance
  • Coastal surveillance
  • Border security


To enable end users to secure their territory against attacks from hostile missiles and aircraft, whether manned or unmanned, HENSOLDT has combined its TRML-4D air defence system (active radar) with its world-leading Twinvis passive radar to form the unique TwinSens solution.


Twinvis is a passive radar that uses existing electromagnetic signals from broadcast and TV transmitters and evaluates their echoes when reflected by an object. It remains invisible and therefore cannot be jammed or eliminated in a targeted action – a real advantage in the military field. More than 15 Twinvis units have already been sold.


TRML-4D is a multi-functional C-band AESA radar for surveillance, target acquisition and weapon assignment. It provides a recognised air picture of the theatre. The radar is able to detect, track and classify various types of air targets, including cruise missiles, hovering helicopters and small, fast, low-flying and manoeuvring aircraft. More than 50 units from the 4D family have already been sold.

Technical features

  • Instrumented range of 250 km
  • Track accuracy:
    • Azimuth: <0.2°
    • Elevation: <0.3°
    • Range: <15 m
  • Dual-band surveillance: NATO G-band (active radar); FM, DVB-T, DAB (passive radar)
  • RF on/off switching time of 1 s

Main benefits

By combining two HENSOLDT systems, TwinSens offers unique functionalities and operational advantages. The exchange of sensor data between these two systems and common control enhances the performance of the overall solution compared to standalone sensors.

With TwinSens, customers get an air picture that is initially created without RF transmissions and consequently without the risk of GBAD systems being detected by enemy forces. This radar solution shows increased resistance to modern jammers and improves situational awareness, even for targets with an extremely small RCS.


Acting under the principle of ‘Detect and Protect’, HENSOLDT has built up a comprehensive product portfolio and an excellent customer service.



TwinSens on screen