passive optical surveillance system

passive surveillance system

passive electronically scanned array (PESA) / passive phased array

electro-optical system

electro-optical warfare system

optical maser system

surveillance, high- and low-altitude surveillance

surveillance, under surveillance

heat passive homing guidance system

passive homing system

passive orientation and damping system

tank passive pitch and roll damping system

passive detection system

electro-optical countermeasures

electro-optical sensor

optical decoy

optical device

optical electronic countermeasures

optical flash

optical gas mask

optical homing

optical intelligence

optical mine-hunting

optical munitions

optical range

optical relay

optical sight

optical target-sensor

optical tracking

artillery optical reconnaissance

helmet-mounted optical display

optimized optical link helmet-mounted display

optical communication