A few weeks ago the Russian military started a systematic counter artillery campaign which has since made great progress. The typical western way of detecting enemy artillery units is by radar. The flight path of the projectile is measured and the coordinates of its source are calculated enabling ones own artillery to respond. But counter-artillery radar itself depends on radiating. It is thereby easily detectable and vulnerable to fire. Over the last months Russia deployed a very different counter-artillery detection systems with the rather ironic name of Penicillin:
Penicillin or 1B75 Penicillin is an acoustic-thermal artillery-reconnaissance system developed by Ruselectronics for the Russian Armed Forces. The system aims to detect and locate enemy artillery, mortars, MLRs, anti-aircraft or tactical-missile firing positions with seismic and acoustic sensors, without emitting any radio waves. It locates enemy fire within 5 seconds at a range of 25 km (16 mi; 13 nmi). Penicillin completed state trials in December 2018 and entered combat duty in 2020.
The Penicillin is mounted on the 8x8 Kamaz-6350 chassis and consists of a 1B75 sensor suite placed on a telescopic boom for the infrared and visible spectrum as well as of several ground-installed seismic and acoustic receivers as a part of the 1B76 sensor suite. It has an effective range for communication with other military assets up to 40 kilometres (25 mi) and is capable to operate even in a fully automatic mode, without any crew. One system can reportedly cover an entire division against an enemy fire. Besides that, it co-ordinates and corrects a friendly artillery fire.