These are vectored through a datalink. The aircraft computer display in the pilot’s head-up display (HUD) shows the waypoints to be followed to intercept the bomber.
Link-4A is one such data link. It is a non-secured two-way datalink used for providing vector commands to combat aircraft. It operates in UHF band at a data rate of 5kbps. It follows time-division techniques. Also, aircraft are communicated during the following processes: automatic carrier landing system (ACLS), air traffic control (ATC) and during combat strikes.
Generally, Link-4A’s transmissions are not secure and could be jammed by enemy ECM. On the positive side, it is considered easier to operate and maintain. Because of these reasons, this very old datalink is still being used by the US Navy. In a carrier, there are ten channels for this link and the typical range is as far as 500km.
Link-11. Link-11 is a half-duplex high-speed encrypted datalink. It operates in HF and UHF bands. It facilitates computer-to-computer digital data communication between aircraft and ships. Even if the signals are intercepted by the enemy, these cannot be understood by them because of the encryption. Data can only be decoded at the receiving terminal.
Positional information of the transmitter is also sent along the data so that the receiver can know the sender’s position. This feature is an important aspect of combat communication. Typically, data sent by a ship to the aircraft is received by appropriate receivers in the aircraft. There, these are decoded by decoders and sent to the aircraft computer.
Then, information is displayed to the pilot in a format that he or she can understand. Data can be anything like waypoints that have to be followed for reaching the new destination or positional data of the enemy combat aircraft.
Combat aircraft have an electronic system called moving map display, which displays the map of the terrain over which the pilot flies. As the pilot flies ahead, the map also scrolls up accordingly. Waypoints are updated in the display through this datalink. In the carrier, there are 62 Link-11 datalink channels available. Each datalink is capable of communicating as far as 300km.
Link-16. Link-16 is a node-less, jam-resistant, high-speed, encrypted digital datalink. It operates in 960MHz-1215MHz band. Based on TDMA technique, it is used by aircraft, ships and even ground forces to exchange their tactical pictures in near-real-time.
Typically, commanders of the CSG at sea can even get tactical pictures around ground forces operating deep inside enemy territory. Link-16 supports exchange of text messages, imagery data and provides two channels for digital voice communications with a data rate of 2.4kbps and/or 16kbps in any combination. The range is around 500km and there are 255 Link-16 datalink channels available in the carrier.
Officer-in-tactical command information exchange sub-system (OTCIXS). This is a two-way UHF satcom based datalink system for intra- and inter-CSG communication. This link supports the exchange of targeting information for multi-targeting of sub-surface, surface and aerial targets. A ship can get radar track data from other ships through this link even while not using its radar at all. This is called over-the-horizon (OTH) targeting.
Tactical data information exchange sub-system (TADIXS) downlink. This is a shore-to-ship one-way satellite datalink for the ships to receive mission plans for launching Tomahawk Land Attack Missiles (TLAMs).
Sonobuoy datalink. This datalink connects sonobuoys with the under-sea warfare system present in destroyers. These dispensable sonobuoys are dropped by the submarine hunting helicopters in the areas suspected with enemy submarine activity. The under-sea warfare system deduces the submarine scenario through these datalinks.
In a carrier, the storey above the flight-deck is called flag bridge. Commander of the CSG controls all operations from a command centre called tactical flag command centre (TFCC), situated in this bridge. In naval parlance, flag indicates something related to the commander of a fleet.
Commander of the CSG gets instructions from his high command through a satellite based C2 system called global command and control systems-maritime (GCCS-M). Through this system, commander of the CSG provides situation reports to his high command.
A system called advanced combat direction system (ACDS) creates the tactical picture around the CSG. Display of the ACDS gives the CSG commander the tactical picture around the CSG for taking combat decisions.
Similarly, captain of the carrier has another parallel ACDS display at his command centre called combat direction centre (CDS) from where he or she gets the tactical picture around the carrier.