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By Norman Friedman, Author, Naval Institute Guide
Tomahawk Spin-offs
A striking but generally unnoticed success of the embargo against Iraq was the U.S. Navy’s hybrid surface surveillance system. The system was developed to support the Tomahawk ship attack missile, but, as the embargo showed, it has much more general application.
Tomahawk is unique among U.S. surface weapons in that its range exceeds the launching vessel’s sensor horizon. Harpoon range, in contrast, is just at the edge of electronic support measure (ESM) range. Moreover, the Tomahawk flies relatively slowly, so that if it is fired at a moving target’s last known position, the target will have moved some considerable distance before it arrives. Since there is no way to update the missile in flight, the surveillance system supporting it must project ahead likely target position, or the missile will be forced to spend time searching—time that may expose it to enemy antiaircraft fire.
The USS Princeton (CG-59) fired this Tomahawk during Desert Storm. The missile proved its effectiveness, but that is not the whole story—its development spawned a command and control system with broad capabilities.
The Tomahawk was conceived about 1973. It quite clearly provided the U.S. Navy with a new and potentially valuable capability but was practical only if the capability did not cost too much. The Soviets had developed a rather elaborate ocean surveillance system, which the West calls the SOSS (Soviet Ocean Surveillance System), specifically to support attacks by long range stand-off missiles such as the SS-N-3, the Soviets’ closest equivalent to the Tomahawk. Even so, the Soviet missile required inflight updates.
The U.S. Navy would not accept a similar update system for Tomahawk, because any emission by a U.S. surface ship or submarine would increase the danger of counterattack.
The SOSS is expensive because it is a dedicated system of shore radio
direction-finders, ocean-surveillance satellites, and long-range radtn* airplanes (Tu-95 Bear Ds). Its sensors work well together to generate a picture of U.S. naval activity. Even so, the SOSS probably does not form anything remotely like a complete picture of ocean traffic in its area of interest.
It is unlikely, for example, to be aware of non-targets, such as neutral merchant ships, near a potential target such as a carrier. Thus it cannot always be sure that a weapon aimed at the carrier will not instead hoWe on one of the non-targets. Too, the SOSS relies very heavily on the target s own emissions, so that radio and radar silence can frustrate it- The SOSS probably uses a classical manual plot to summarize the infot" mation it receives from its various sensors.
Some in the U.S. Navy wanted to build a U.S. equivalent. Specia1 radar satellites would track all shipping. Powerful computers would sort the radar data (ultimately, perhaps, imaging radars would be used, with automatic pattern-recognizers). The problem was that surface ships were seen as a peripheral concern—Soviet submarines and bombers were the main wartime Soviet threat. It would indeed have been very useful to deal rapidly with the Soviet surface fleet, but only if the expenditure for that purpose did not preclude more urgent projects.
About 1975 an alternative was suggested. The United States already was collecting a great deal of information about surface ships. Satellites detected many of their radio signals, for example, but little of this data was passed to the Navy; it was a spin-off from “national-level” pr°' grams run by interservice intelligence agencies such as the National Security Agency (NSA).
But the data contained much of the sort of sea-surveillance information that would be needed by Tomahawk shooters. Granted, it had to be sanitized, brought together, and collated, but once that had been done, track data could be transmitted as such, shorn of the security restrictions applied to national-level intelligence.
An experiment designated Outlaw Hawk-Outlaw Shark, was conducted in the Mediterranean (Hawk stood for the carrier Kitty Ho»’k (CV-63) while Shark was a submarine). Track formation and collation were conducted at shore stations with large computer capacity and the data were transmitted by secure channel to the simulated missile shooters. Each missile-shooter had its own computer to keep track of the over-the-horizon (OTH) picture, potentially out to 1,500 nautical miles.
The experiment was successful and one result was that each carrier (and several other ships) were provided with OTH track-keepers, which became part of the Tactical Flag Command Center (TFCC). The Outlaw Shark track-keeper was also incorporated in the Tomahawk Weapons Control System, which was then in the design stage.
Track collation at the time required large computers, but smaller computers quickly became powerful enough so that virtually every ship could be fitted with a work station sufficient for track collation. The track-collating system, then, became decentralized. Any ship in the net could be made responsible for track collation, or any ship could be made responsible for handling some particular aspect of track-keeping. The new desk-top (actually work station) computers could all be provided with software for the statistical estimation of future ship positions and there is now a standard Navy software package for this purpose, developed by Tiburon Systems. The computers are all connected to a series of secure data links the Officer in Tactical Command Information Exchange System (OTCIXS).
Because the system was designed to accept data from quite disparate sensors, and to apply different levels of confidence to their outputs, it easily accepts new sources of information. In particular, a specially modified P-3C, Outlaw Hunter, has proved very valuable during the current embargo on Iraq.
Outlaw Hunter is a P-3C with an inverse synthetic aperture imaging ‘juar (useful for ship identification), a global positioning system (GPS) rcceiver (with which it can accurately associate a ship image with a Position), and a track-keeping computer (in this case, incorporated in the ^ 'uitron Advanced Tactical Workstation). Thus the Outlaw Hunter P-3C, utch had originally been conceived to support Tomahawk shooters, was , e t0 identify merchant ships and the data improved the overall force hack fries. F
This was valuable because the international maritime-interception “rcc consisted of relatively few ships, and merchant ships had to be 1 untilied early if they were to be intercepted efficiently. Any major '"efficiencies would have allowed Iraq to break the embargo by running c blockade. The decentralization inherent in the Tomahawk-oriented ^ea-surveillance system limited the extent to which the interceptors had 0 be directed. The track projection, so important for missile firing, also ltlade interception practical.
b°r ships, tfte main terminal of the surveillance system is a desk-top c°mputer running the Joint Operational Tactical System (JOTS) soft- VVare- Most of the coalition maritime interdiction force required access to ^-surveillance data and, during the fall of 1990, more than 200 JOTS *crminals were installed, even though the system had just passed its oper- at'°nal evaluation.
The achievement illustrates a very new feature of modem computer- or'ented systems. It has now become relatively inexpensive and easy to utultiply such systems, because their hardware represents only a small "action of their overall cost and complexity. The JOTS terminal itself is a standard commercial product, slightly modified lor naval use. The ■ S. Navy bought thousands of such computer work stations, because *bey could be used in numerous systems by varying the soltware.
The software is a different story. It is very expensive to develop but, °nce it has been validated and debugged, it becomes inexpensive. As a result, the 1990 JOTS experience in the Gulf has wide application.
The cost of n-systems is no longer even remotely like n times the cost a single system. It is much closer to the cost of a single system, so that uying numbers of more or less identical combat or other systems may be preferable to buying small numbers. Moreover, we may finally e seeing in some military systems the sort of cost reductions we have c°me to expect in civilian electronics, as single chips replace large hard- 'v'red devices. Certainly the sudden deployment of more than 200 major c°mmand and control systems has no precedent. That it went almost Unnoticed save for those involved says even more.
Overall, the embargo proved that, without deploying any specialized nardware, the U.S. Navy could indeed maintain a current picture of all sUrface traffic in a large ocean area. The decision, made about 15 years ago, to emphasize data processing rather than to build new sensor sys- lems to support Tomahawk was very largely vindicated. The track-colla- bon software is now at sea on board Tomahawk shooters—Combat Con- troi Systems (CCS) on submarines and Tactical Warfare Control Systems (TWCS) on board battleships, cruisers, and destroyers.
The system does not quite correspond to the SOSS but suffices against ships operating alone. The Soviets, however, have long appreciated that a missile approaching a formation of ships could easily acquire and hit "he wrong ship. They have always respected the staying power of U.S. carriers, and have endeavored to make sure that all or most of the weapons fired at a carrier battle group struck the right ship. Their solution has been the tattle-tale, a surface ship or submarine that shadows the battle gfoup and sends back the position of the carrier within the formation. Soviet destroyers have been converted to a special tattle-tale configura- bon, and carry antiship missiles that fire aft over their sterns as they turn aWay from the formation before the Soviet missile attack.
The U.S. Navy, in contrast, could not really accept the tattle-tale Concept. It had to accept that the Soviets might well fire first, and thus bestroy any nearby U.S. tattle-tale. The choice eventually seems to have been to provide Tomahawk with some means of identifying specific Soviet ships. Initially that meant using special characteristics of their electronic emissions. Ultimately, it probably means providing the Tomahawk radar seeker with an inverse synthetic aperture radar mode and sufficient intelligence to distinguish between the ships of a formation, a "ask that should not be insuperable, since the sea surveillance system will have identified the ships (or at least the classes) within the formation in advance, thus limiting the information the missile needs when it is launched.
The advent of Tomahawk, then, has had enormous impact on the U.S.
Navy’s command and control structure, probably far beyond what its advocates could have imagined when it was conceived.
After all, the Tomahawk was a useful strategic bargaining chip that became a useful tactical weapon. Its impact on the fleet was carefully limited. The land-attack version, for example, has its targeting done by shore stations, because targeting is so complex an affair. (An afloat mission-planning system is nearly ready.)
The Tomahawk antiship missile as developed had more range than the Navy could use. The service’s efforts to exploit this capability without buying a special Tomahawk targeting system have caused a decentralization of its tactical intelligence system. This decentralization was a major impetus for the development of the new Copernicus command-and- control architecture. (See “Copernicus Offers a New Center of the Universe,” Proceedings January 1991, p. 86.)
All of this is quite apart from the missile’s success against land targets in the Gulf War. There, missiles were used as precursors for manned aircraft strikes, destroying key Iraqi radars for the strike version of the missile in future. Such operations are now relatively complicated, because the missile’s flight path has to be specified in great detail before it can be launched. Current practice is for large numbers of missions to be planned at ashore Tomahawk Missile Planning Centers. Mission data are then collected in Data Transfer Devices (DTDs), essentially large removable hard disks, and physically taken aboard the launching ships. The afloat planners can review the Tomahawk missions to select those they wish to use. They can also overlay Tomahawk and tactical air strikes to combine the two most effectively.
The land-attack missile still has some important limitations. First, it finds its position by comparing its altitude with a series of stored ground heights. Successful attacks are therefore limited to areas that have been mapped in detail, and the missile must fly for some time over the land before it hits its target.
Second, since the strike packages are developed ashore (and physically carried on board ship), it is difficult for a naval force to use Tomahawk in a suddenly-developing crisis. This is most unfortunate. If indeed the Soviet threat is fading, and the future U.S. military establishment is to be oriented more against Third World threats, then the most important virtue is flexibility. The Third World is fundamentally unpredictable. We may often be able to influence events merely by an impressive presence, but sometimes we may have to fight when we arrive. Had Saddam Hussein continued on from Kuwait into Saudi Arabia (as many expected), the war would have begun in August 1990, not the following January. With only two or three carriers on station. Tomahawks would have been even more important than they became later.
Fortunately, solutions to these problems are in train. The next version of Tomahawk, Block III, will incorporate a GPS receiver and will not have to rely on terrain comparison. The GPS has already demonstrated impressive capability in the night ground attacks that began Desert Storm, and in the performance of the standoff land-attack missile (SLAM). A GPS-guided Tomahawk should be able to approach a target directly from the sea, adding approach flexibility that should make it even more difficult for a prospective target to guess its line of approach.
Targeting flexibility is also improving; the fleet should begin to receive the new afloat planning system in 1992. The succession from shore to afloat mission planning recalls the evolution of Polaris-Poseidon fire control. When the first Polaris submarines went to sea, they carried on board decks of prepunched cards representing their assigned sets of targets. Computation was simply too elaborate to be possible in a cramped submarine at sea. Then the submarines began to carry a computer that could punch out the cards, though not in real time. Decks of cards were needed because the submarine had to be able to aim her missiles from any point within her patrol area. In the final stage, Poseidon, a geoballistic computer keeps track of the submarine’s position and constantly updates the targeting data for each of the 16 missiles.
Tomahawk is much more complex because it maneuvers freely in flight. Its path can, for example, be planned to avoid antiaircraft batteries and obstacles. That sort of detail involves massive amounts of data, and using it demands considerable computing power. Now, as in the antiship side of Tomahawk, that sort of power is no longer either massive or expensive. Once the afloat planning system is in place, the combined force of naval tactical aircraft and Tomahawk shooters will once again be able to respond instantly to unexpected contingencies. That flexibility is, after all, the single greatest virtue of U.S. naval forces in a very unstable world.