EQUIPMENT CONFIGURATION

GEODETIC POSITIONING. —The Link-16 messages use the geodetic coordinate system to report positions. This system uses latitude, longitude, and altitude to report positions anywhere in the world. Link-11 uses the Cartesian coordinate system, which requires the reporting unit to be within a certain range when reporting positions. RELATIVE NAVIGATION. —The Relative Navigation (RELNAV) function of the Link-16 system is automatically started by every Link-16 participant and is constantly operating. The RELNAV function determines the distance between reporting units by measuring the arrival times of transmissions and correlating them with the reported position of the unit. This information is required by each terminal in the network to maintain synchronization. The RELNAV data can also improve a unit’s positional accuracy. Also, if two or more units have accurate geodetic positions, RELNAV can provide all other units with accurate geodetic positions. ELECTRONIC WARFARE. —The Link-16 system increases the types and amount of electronic warfare information that is exchanged between units. LAND POINTS AND TRACKS. —The Link-16 system adds Land as a track category, and allows the reporting of land objects, such as buildings or vehicles. EQUIPMENT CONFIGURATION Currently, Link-16 will be installed onboard aircraft carriers, cruises, destroyers, and amphibious assault ships. Two phases of shipboard installation, designated Model-4 and Model-5, are planned. Model-4 is being installed on ACDS and AEGIS platforms in conjunction with the installation of the Command and Control Processor (C2P). Model-4 does not implement any of the expanded data exchange capabilities of Link-16. Instead, it supports existing Link-11 and Link-4A with its jam-resistant, increased capacity waveform. Platforms with the Model-4 Link-16 system will retain their original 7-8 Link-11 and Link-4A systems, and can use these systems by placing the C2P in bypass. Model-4 is being installed on very few ships, most of which will be upgraded to Model-5; therefore, our discussion of Link-16 equipment will concern the Model-5 system. Link-16 Model-5 The major components of the Link-16 system are the Tactical Data System (TDS), the C2P, and the JTIDS terminal, as shown in figure 7-6. The TDS and C2P provide the JTIDS terminal with tactical data to be transmitted. The Link-16 Model-5 fully implements all the capabilities of Link-16. For this implementation to take place, major software changes must be made to the TDS and C2P programs. Also, the OJ-663 console replaces the current display Figure 7-6.—The Link-16 Model-5 ACDS system block diagram. Data flow to the Link-16 JTIDS terminal is from the ACDS computer, through the C2P computer, to the Link-16 computer. Link data generated by the ACDS computer is now normalized to be independent of any one particular link system. The C2P computer reformats the normalized data into the format necessary for transmission over Link-16. The C2P computer can also format the normalized data for transmission over Link-11 and Link-4A. If necessary, all three link systems can be in operation at the same time.