Although you may be involved in the operation of search radar, the majority of your work will be with radar systems used to control the direction and fire of gun and missile systems. These radar systems are normally part of a larger system. They are called Gun Fire Control Systems (GFCS) or Missile Fire Control Systems (MFCS). Some systems may be able to control the fire of either guns or missiles. These are

Figure 2-3.-USS Nimitz (CVN-68).

simply called Fire Control Systems (FCS). This section will look at the radar associated with these gun and missile fire control systems.

MK 7 AEGIS FIRE CONTROL SYSTEM RADAR

The Mk 7 AEGIS Weapon System is installed on ARLEIGH BURKE class destroyers (fig. 2-4) and TICONDEROGA class cruisers (fig. 2-5). The Mk 7 AEGIS system contains the SPY-1 radar system, the

Mk 99 Missile Fire Control System (MFCS) and the Mk 86 Gun Fire Control System (GFCS) or the Mk 34 GWS (Gun Weapon System). We will discuss each of these systems briefly as they relate to their associated radar systems.

AN/SPY-1 Radar

The latest technology in multi-function radar is found in the AN/SPY-1 series on TICONDEROGA class cruisers and ARLEIGH BURKE class

Figure 2-4.-AEGIS class destroyer DDG-60 USS Paul Hamilton.

Figure 2-5.-USS Ticonderoga CG-47.

destroyers. Ships that do not use the AN/SPY-1 are being upgraded to a system known as Ship Self-Defense System (SSDS). We will discuss SSDS in another section.

For more than four decades, the U.S. Navy has developed systems to protect itself from surface and air attacks. After the end of World War II, several generations of anti-ship missiles emerged as threats to the fleet. The first anti-ship missile to sink a combatant was a Soviet-built missile that sank an Israeli destroyer in October 1967. This threat was reconfirmed in April 1988 when two Iranian surface combatants fired on U.S. Navy ships and aircraft in the Persian Gulf. The resulting exchange of anti-ship missiles led to the destruction of an Iranian frigate and a corvette by U.S.-built Harpoon missiles.

The U.S. Navy's defense against this threat relied on a strategy of gun and missile coordinated defense. Guns were supplemented in the late fifties by the first generation of guided missiles in ships and aircraft. By the late sixties, although these missiles continued to perform well, there was still a need to improve missile technology in order to match the ever-changing threat. To counter the newer enemy missile threat, the Advanced Surface Missile System (ASMS) was developed. ASMS was re-named AEGIS (after the mythological shield of Zeus) in December 1969.

The AEGIS system was designed as a total weapon system, from "detection" to "kill". The heart of the AEGIS system is an advanced, automatic detect and track, multi-functional phased-array radar, the AN/SPY-1. This high-powered (four-megawatt) radar can perform search, track, and missile guidance functions simultaneously, with a capability of over 100 targets. The first system was installed on the test ship, USS Norton Sound (AVM-1) in 1973. Figure 2-6 shows the weapons and sensors on an AEGIS class cruiser.

The system's core is a computer-based command and decision element. This interface enables the AEGIS combat system to operate simultaneously in anti-air warfare, anti-surface warfare, and anti-submarine warfare.

The AN/SPY-1 series radar system works with two fire control systems on AEGIS class ships: the Mk 99 Missile Fire Control System and the Mk 86 Gun Fire Control System (part of the Mk 34 Gun Weapon System). The Mk 86 GFCS is also found on SPRUANCE class destroyers and works with the Mk 91 Missile Fire Control System. We will discuss the Mk 91 MFCS in a later section.