External Communications Subsystem

HARPOON MISSILE WEAPON SUBSYSTEM The HARPOON missile weapon subsystem provides a self-contained, surface-to-surface missile system capable of launching the HARPOON missile at over-the-horizon surface targets. The HARPOON missile weapon subsystem is the ship’s primary surface-to-surface weapon. The subsystem relies on the weapon control processor (WCP) computer and other elements of the combat system for target detection, threat evaluation, weapon pairing, and target data functions. EXTERNAL COMMUNICATIONS SUBSYSTEM The external communications subsystem allows the ship to transmit and receive commands, orders, instructions, and reports. Its primary purpose is to fulfill tactical and operational command communication requirements; its secondary purpose is to meet essential administrative requirements. The external communications subsystem includes antenna systems, transceivers, transmitters, receivers, terminal equipment, and security equipments. Several configurations may be used for transmitting or receiving with these equipments. Duplex, simplex, or receive-only operation may be used with both secure and nonsecure teletype and voice systems. Duplex operation provides simultaneous transmission and reception, and is used for specific operations involving the passing of data. Simplex operation provides communication between two stations in only one direction at a time. It is most commonly used on voice, data, and continuous wave (cw) circuits. Receive-only (broadcast method) is used for many teletype, facsimile, and continuous wave (cw) operations, where receipt acknowledgement for each message is not required. Communication services provided by the external communications subsystem are voice, teletype, digital data, high frequency (hf and ultra high frequency (uhf) relay, and very high frequency (vhf) homing. Voice communication services are provided on the R, U, Y, vhf bridge-to-bridge and fleet satellite communication (SATCOM) secure voice, and underwater communication circuits. The terminal configurations consist of the C, G, N, R, Sa, Sd, W, and single audio system (SAS) configurations. The Naval Modular Automated Communications System (NAVMACS A+) is provided as a special facility. The Link 11 circuit provides for interchange of track data, weapon system status, and commands. This is done on a digital link between naval tactical data system (NTDS) ships, certain airborne early warning facilities, and antisubmarine warfare aircraft via hf or uhf. The Link 11 circuit is the primary means for Figure 4-3.–External communications subsystem (Link 11). 4-6