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.
