 The enemy may attempt to avoid the directional radar systems or even use electronic countermeasures, so active patrolling, and activating the radar at random times and in random directions will act as a counter-countermeasure.Complementary acoustic and electro-optical systems can compensate for the lack of omnidirectional coverage by the AN/TPQ-36 and AN/TPQ-37.To complement the counterartillery radars, additional MASINT sensors include acoustic and electro-optical systems.