The missile’s seeker uses a TV camera, or in later generations, a Charged Coupled Device (CCD). The operator locks the seeker onto the target. The seeker then keeps the target centered in its field of view until impact. Some seekers are daylight only. These are listed as EO(D). Others are sensitive to low light levels, and can operate in day or night. These are listed as EO(DN). Imaging Infrared EO(IIR) seekers are all day/night capable. The first EO weapons were introduced in the late 1960s. As the technology improved, the seeker’s range (the distance at which it could see the target and be locked on) increased, as well as its ability to see at night or poor weather, and its ability to distinguish a target from the background. Dust, smoke, mist, and fog can obstruct the visual line of sight, but EO seekers are immune to radar or IR jammers and chaff. Weapons with EO seekers can attack ships or ground targets. First and second generation seekers cannot lock onto moving ground targets, but third-generation seekers can. EO missiles are locked onto the target by the operator before launch. Once launched, the aircraft does not and cannot control it. He can maneuver freely or fire another weapon. The target must be within visual line of sight of the launching unit when it is fired. An operator may launch as many EO missiles as the rate of fire allows. While locking the seeker on the target, the operator is “heads down” in the cockpit, and cannot perform any other action. If the plane is a single-seat aircraft, the pilot cannot fire any other weapon or maneuver defensively. If he does, the launch is aborted. If the plane is a two-seater, the pilot can maneuver and fire other weapons while the weapons system operator deals with the EO weapon launch. Some EO weapons have Data Links. These will have (DL) added to their guidance, e.g., EO (IIR, DL) or EO(DN, DL). The link allows an operator (not necessarily the launching unit) to see what the seeker sees after launch, and correct or improve the aim point. Aircraft with a data link, carried either internally or as an external pod, can control EO weapons in flight. Aircraft without data links cannot, even if the weapon has the Data Link feature. A missile with a data link can be locked onto the target after launch. The firing unit (which does not have to be the controlling unit) does not have to have a line of sight to the target at launch. The operator must lock the missile onto the target before the missile is within one 30- second Engagement Turn of the target, and the operator must have a visual LOS to the missile when he makes the lock. Before and after that, he can maneuver freely or fire another weapon. He can only lock one inflight missile onto a target at a time. BT Back to The Naval Sitrep # 24 Table of Contents Back to Naval Sitrep List of Issues Back to MagWeb Master Magazine List © Copyright 2003 by Larry Bond and Clash of Arms. This article appears in MagWeb.com (Magazine Web) on the Internet World Wide Web. Other military history and related articles are available at http://www.magweb.com