Most medium-to-large warships usually have an Early Warning/Volume Search radar in addition to the main one for long-range target detection. While researching such systems I came across a certain peculiarity: Modern Russian ships generally use the 3Ts-25 Garpun and Mineral-ME volume search radars, which advertise a passive detection capability.

Aside from the usual radar transmitting antenna, these systems have an additional antenna element that simply receives signals from other radars, identifies and pinpoints them, like a passive listening station. This enables them to detect targets as far as 450km using their own radar emissions.

I don’t know the specifics of how such systems work, but in theory it seems to me an excellent idea for today’s warships, hearing all the praise about how powerful and long-ranged modern radar systems like the Type 45’s are. Why is it that there is no Western analogue to such systems i.e. a passive radar system for the volume search role?

Afaik, Mineral ME and Garpun are 2D (range and bearing) radars used specifically for OTh AShM targeting. For which Western ships tend to use organic heliborne radar and shipborne 3D radar and ESM and networked off-board RADAR/ELINT/ESM assets.