Those drones fly undetected by radar, they are too small and made out of plastic to be detected by radar, in fact the best way to detect and target them would be with the sound and ground observers ploting their estimated flight path and by visual, thermal or infrared targeting. The radar of these systems is targeted by the ka52 I believe.
It can detect both Tanks and Armored Vehicles by radar plus it detects radar emitting equipment from well out of the range, even the anti air is simply another target for them, onto which they can lock on from almost behind the horizon.