Some airports use active countermeasures, ranging from a person with a shotgun through recorded sounds of predators to employing falconers.

They'll use heavy passive and active electronic countermeasures too.

They'd nodded approvingly and gone on to discuss the virtues of active countermeasures versus low-observability systems.

None of the revolutionary cadres had got that far into the castle, or survived the active countermeasures.

Against the ASW weapon itself, both active and passive countermeasures are used.

Defense countermeasures are often subdivided into "active" and "passive" countermeasures.

This may force future stealth platforms to stand off from their targets and use active countermeasures and long range weaponry to strike targets.

The most active countermeasure is 2 . . . Ne4.

But what would the active countermeasures be?

I guess I was wondering if they have active countermeasures, as well.