Mk 92 Fire Control System on PERRY class frigate

figure 2-16). All associated electronics for radar operations are enclosed within either the radome or the Electronics Enclosure (called the ELX). CIWS is operated remotely from either a Local Control Panel (LCP) or the Remote Control Panel (RCP) located in the Combat Information Center (CIC). It has two primary modes of operation: automatic and manual. In the automatic mode, the computer program determines the threat target, automatically engages the target, and performs the search-to-kill determination on its own. In the manual mode, the operator fires the gun after CIWS has identified the target as a threat and has given a “recommend fire” indication. CIWS was developed in the late 1970’s to defend against anti-ship cruise missiles. However, as the sophistication of cruise missiles increased, so did the sophistication of CIWS. Major changes to CIWS are referred to as “Block” upgrades. The first upgrade, known as “Block 0”, incorporated a standard rotating search antenna. Limitations of elevation in Block 0 lead to the next upgrade, Block 1. Block 1 provided improved elevation coverage and search sensitivity by using a phased-array antenna. A minor upgrade to Block 1, known as Block 1A, improved the processing power of the computer by incorporating a new high-order language. This upgrade gave CIWS the ability to (1) track maneuvering targets and (2) work with multiple weapons coordination. The next upgrade, Block 1B, enabled CIWS to engage surface targets. This upgrade is known as the Phalanx Surface Mode (PSUM). A special radar, Forward-Looking Infrared Radar (FLIR), was added to CIWS to detect small surface targets (i.e., patrol/torpedo boats) and low, slow, or hovering aircraft (i.e., helicopters). This radar is mounted on the side of the radome structure. FLIR can also help the radar system engage anti-ship cruise missiles. To detect targets day or night, CIWS Block 1B uses a thermal imager and advanced electro-optic angle tracking. 2-11 Figure 2-14.—Mk 92 Fire Control System on PERRY class frigate. Figure 2-15.—WMEC-910 Coast Guard Cutter Thetis with Mk 92 CAS.