Micro-Doppler, Not Metal Grills: APS Takes on the Drone Threat

Image by @Grok

Russia's Mechanical Engineering Design Bureau (JSC NPK KBM) in Kolomna has patented a new technique to safeguard tanks from drone attacks. Existing MBT (Main Battle Tank) active protection systems (APS), such as the Arena-M fitted on the T-90M, are designed to detect, track, and engage fast-moving ATGMs and shells. However, they are ineffective against small battlefield kamikaze drones.

Overcoming the Challenge

Small drones flying at low speeds generate weak RF reflections and are therefore ignored by the APS as background clutter. The patented technique does not attempt to detect the drone directly. Instead, it detects a drone indirectly by sensing the distinctive scattering pattern of RF signal reflections generated by the drone’s propellers.

Propeller blades create a characteristic micro-Doppler signature that is normally interpreted as “radar noise.”

In Patent No. 2853544, published in the database of the Federal Institute of Industrial Property (FIPS), KBM developers propose hardware and algorithmic modifications to the radar sensor that allow the APS to additionally handle drone threats. The radar periodically switches from a long-range detection mode—optimized to detect and track missiles and shells—to a short-range detection mode optimized for drones using the patented technique.

This allows the radar to seamlessly track both high-speed threats and slow-moving drones.

It would be possible to upgrade existing Arena-M APS installations with the patented hardware and software, giving T-90M “Breakthrough” tanks a dedicated counter-drone capability.

The existing Arena-M complex reportedly features a multifunctional radar station with high noise immunity for threat detection. For threat engagement, it employs quick-activation ammunition placed along the perimeter of the tank turret in dedicated installation shafts.

Copyright © Vijainder K Thakur. First published on Thumkar.

Beating the Heat: How Anti-Thermal Cloaks Are Changing Drone Warfare

Beating the Heat: How Anti-Thermal Cloaks Are Changing Drone Warfare

My analysis at https://t.co/5oJ1HhoITm

Russian troops reportedly used anti-thermal cloaks to evade detection by surveillance drones equipped with thermal-imaging (TI) sensors, allowing them to penetrate… pic.twitter.com/2MqomErvco

— Vijainder K Thakur (@vkthakur) December 3, 2025

Russian troops reportedly used anti-thermal cloaks to evade detection by surveillance drones equipped with thermal-imaging (TI) sensors, allowing them to penetrate Ukrainian lines in Krasnoarmeysk at night.

The troops entered Ukrainian-held territory despite the presence of enemy drones, ambushed equipment and personnel, and mined roads to cut off supply lines—leaving the adversary confused and disorganised.

The cloaks—nicknamed “anti-drone raincoats” due to their poncho-like design and waterproof qualities—incorporate insulating and reflective materials such as nylon with embedded aluminium or silver particles, or layered Mylar (a reflective foil-like material) sandwiched between fabric.

These “raincoats” prevent the escape of infrared (IR) radiation emitted by the human body, which TI sensors detect as heat signatures. Their outer surface remains close to ambient temperature, reducing the thermal contrast needed for TI detection.

They are particularly effective during “thermal crossover” periods, when air and ground temperatures are nearly equal. This typically occurs after daybreak and sunset, as well as in rain or fog. During the day, the raincoats can also be effective when troops remain close to objects such as rocks or vegetation that are warmer than the surrounding air.