||Histories for Combat Systems Techincal School Command, Mare Island
Histoory of NTDS
The following two part article was published in the Hughes Aircraft Company, Ground Systems Group Chronicle, Vol. 3, No. 9-10, October-November 1988, Fullerton, California.
NTDS: From the old world to the new
The following is the first of a two-part story based on an historical paper written by three naval engineers involved in the implementation of the Naval Tactical Data Systems (NTDS). One of the authors, Capt. Erick N. Swenson, USNR (Ret.), is a project manager for special projects in the Surface Ship Systems Division (1D).
By Erick Swenson
A little over 30 years ago, the Bureau of Ships assembled a group of naval engineers to develop a new system approach to the combat information center (CIC).
The CIC of World War II, with its grease-pencil plots and voice-telling of tactical information from sensors and other ships, could no longer provide the timely, coordinated reaction to postwar threats. This project group led the Navy into the new world of large-scale, high-speed digital electronics and into a new mode of conducting naval warfare.
The development of radar had produced spectacular changes in the conduct of naval warfare. By the Korean War, jet aircraft had replaced their propeller-driven predecessors, and the generation of combat information increased exponentially. The magnitude of the information to be assembled overwhelmed conventional means, and analysis and decision-making bordered on hopelessness. Naval commanders needed to gather and assimilate information faster so they could make decisions as quickly as naval scenarios were then unfolding.
By the early 1950s, several development programs were underway ? by the Bureau of Ships (BuShips), the Office of Naval Research (ONR) and the naval laboratories ? to solve the critical CIC problem. Several of our NATO allies were involved in similar developments.
All the research and development added greatly to the technical understanding of the CIC data-handling problem, but none provided the system approach to meet the multimission requirements for U.S. Navy ships. The cost and complexity of the analog system needed was excessive, but the preferred digital solution was handicapped at the time by the size of vacuum-tube digital computers.
In 1954, Project Lamplight was initiated ? a large tri-service, NATO study at the Massachusetts Institute of Technology ? to formulate recommendations for air defense. Naval members Cmdr. I.L. McNally and E.E. McCown wrote the technical requirements for NTDS. Planners in the Office of the Chief of Naval Operations supported this plan and, in early 1956, endorsed it as the major BuShips technical effort to improve CICs on major combatant warships of the future.
Each ship equipped with NTDS would operate independently, or as a unit of a multiship task force. A building-block approach would be used, using standard computers, displays and communication terminals, to meet the varying requirements of ship types and the changes in sensors, weapon systems and tactics that occur over a ship's lifetime.
While the initial implementation of NTDS would emphasize antiair warfare, system components would be designed with the flexibility to meet the requirements of other missions.
The system would be required to operate continuously. Hence, alternate modes of operation would permit some minimum acceptable level of operation during periods of maintenance or training.
Each ship would be equipped with data links to permit data exchange with other ships, with airborne early warning and interceptor aircraft, and with Marine Corps systems ashore. Each ship would have a net control capability to facilitate a change of net control or force command from one ship to another.
Because of shipboard space limitations and power and heat considerations, only solid-state hardware was to be used. In order to accommodate change, NTDS computers had to be reprogrammable. This need for flexibility dictated the use of general-purpose, stored-program digital computers.
It was necessary to convert the various forms of tactical data to digital representation so that all data and information could be processed digitally. Classes of analog/digital conversions were defined and decisions made as to which could be used in each application. On-line conversion of vital data sources was applied to such selected sensors as the gyro, pit log and primary radars. Some sensors, however, were converted off-line, with data entered by a manual keyset.
Automatic radar detection and tracking of air targets was recognized as an urgent need if the fleet was to handle projected air warfare track volume. All ships would have an initial manual, rate-aided tracking capability for all installed radars, When radars were equipped with radar video processors (RVP), rate-aided tracking would provide backup in case of the RVP?s failure, or when automatic tracking was lost during periods of high false-alarm rates or intentional jamming.
An experimental RVP for air-search radars was installed on the USS Oriskany for technical evaluation. Hughes? AN/SPS-33 radars on two early NTDS ships, the USS Long Beach and USS Enterprise, provided processed track data and effective automatic tracking for a large number of targets. The experience with these three ships provided the knowledge necessary to later develop hardware for other types of radar.
A land-based test site was established at the Navy Electronics Laboratory (NEL) in San Diego where the development system would be installed, operated and evaluated. In addition to testing, an operational team operated and appraised the system.
Seymour Cray of Remington Rand Univac designed the first unit computer. He also resolved the problem of how these computers could ?talk" to each other and to other system components. Six developmental model unit computers, designated the AN/USQ-17, were designed and built for engineering test. Shortly after they were delivered and system tests begun, service test computers designated CP-642/USQ-20 were requested. This computer has evolved into the more powerful UYK-7 and the current UYK-43.
One of the most critical unknowns was that of a computer software capability for real-time systems. The success of NTDS depended upon the ability to create reliable software.
Initial experimental software was developed by Univac; however, it was decided that operational software issuance should be under control of the Fleet. This resulted in the establishment of Fleet Computer Programming Centers responsible for the production, test, reproduction, configuration control and maintenance of the operational programs.
To aid in the development of these programs, the CS-1 and CSM-2 compilers were written. These compilers became Navy standards. Today, Ground Systems Group provides the developmental software for these activities.
This is the second of a two-part story; the first appeared in last month's issue of the GSG Chronicle. The story is based on an historical paper written by three naval engineers involved in the implementation of the Naval Tactical Data System (NTDS). Capt. Erick N. Swenson, USNR (Ret.), is a project manager for special projects in the Surface Ship Systems Division (1D).
By Erick Swenson
In June of 1956, BuShips contracted with Ground Systems Group, for the design of a combined digital and analog display system, suitable for interfacing with the Univac computers. The AN/ SSA-23 prototype display system consoles were subjected to engineering tests at Univac, St. Paul; Hughes, Fullerton; and the Navy Electronics Laboratory (NEL), San Diego.
Additional contracts to study the ruggedizing of the prototype system for service test production and the redesign of the AN/SYA-1 service test system reflected lessons learned from initial testing of the prototype system at NEL. Alphanumeric readouts, sweep circuits and mechanical design were totally redone, improving operation, reliability and maintainability. Greater versatility in the display console design permitted a reduction in console types.
The new NTDS displays were used to present radar digital data on the USS Long Beach and USS Enterprise with their new Hughes electronic scan and automatic tracking radar. The Chief of Naval Operations directed that the NTDS be installed in these ships prior to delivery, as well as in the original three service test ships. Each new display model brought into the fleet incorporated significant improvements ? first the AN/SYA-4, then the AN/UYA-4, and now the current AN/UYQ-21.
The original equipment, the AN/SRC-16 four-radio system complex, had a built-in multicoupler capability that afforded great flexibility in switching between radios and antennas. The AN/SSQ-29 data terminal set converted computer data selected for transmission into phase-modulated tones that modulated the carrier for HF transmission and the protocol and control-code recognition techniques provided net control capability.
A force of combatant ships could operate as though it were a single platform. This close coordination, control and application of all force assets resulted in an operational jump in combat capability for the U.S. Navy. The message standards and protocols generated by the Bureau of Ships (BuShips) in July 1957 were subsequently accepted by the Tactical International Data Exchange Committee established by Canada, the United Kingdom and the United States. Later, these became NATO standards and are currently used by all the allied navies using NTDS-type hardware.
A shipboard terminal was developed for the BuAer-developed automatic ground-to-air high-speed serial link for installation in the Navy?s newest fighter aircraft. Known as Link 4, it permitted shipboard communication with aircraft for intercept control and for air traffic and landing operations.
The USS Oriskany and two new construction ships, the USS King and the USS Mahan were selected for service evaluation of the NTDS. An extensive evaluation was conducted from October 1961 through April 1962. Concurrently, BuShips conducted a technical evaluation of the systems. NTDS equipment reliability was judged outstanding and clearly demonstrated that Navy personnel could operate and maintain the systems.
As a result of a cooperative effort between the NTDS training group at NEL and the Bureau of Personnel Field Activity at San Diego, a new rating, data systems technician, and a new school at the Naval Schools Command, Mare Island, were created. The six-month to one-year training program for data systems technicians enhanced their self-image, capability and maturity. These technicians were able to keep the new gear running, and felt competent doing so. The new rating was a major change in enlisted career possibilities.
Notable NTDS accomplishments
? First shipboard tactical data system in the world to use stored-program, solid-state digital computers. First to use multiple computers in a distributed, tactical data processing system.
? First land-based test site to check out and evaluate a complete tactical data system.
? First Fleet Computer Programming Center completed and commissioned.
? First shipboard system in the world to use automatic computer-to-computer data exchange between ships, and between ships and aircraft.
? First major step in achieving an integrated combat system. The coordinated design achieved a new level of system integration and interface definition for the CIC and the weapons control systems.
? First Navy implementation of a computerized ?expert? system for threat evaluation and weapon assignment.
By early 1957, a team of naval engineers was in place at BuShips. Additional military and civilian engineers were assigned through the ensuing years of NTDS development. The NTDS Project Office team included then-Lt. Erick N. Swenson, USNR.
Key to the NTDS program's success was the close cooperation among the Washington headquarters, the NEL in San Diego, the BuShips staff and the Office of the Chief of Naval Operations.
The Navy was the design agent. No one company was believed to possess the ability to develop all the items that comprised the system. By the end of 1956 the initial development hardware and design contracts were awarded, by specialty, to several contractors:
? Univac for computers, system design assistance and software;
? Hughes Aircraft Company for displays;
? Collins Radio Company for NF data links; and
? many small companies for selected items.
In the 25 years since deployment of the first NTDS-equipped ships, and after operational use by several hundred ships, the basic system remains fully functional. The inherent flexibility of the system has accommodated changes in sensors, weapon systems and the tactical environment, permitting repeated updates of the building-block computers, displays and data links. The system is expanding to support electronic warfare, antisubmarine warfare and other warfare categories.
Enthusiastic acceptance of the system is best illustrated by a message from the commander of a task force group:
?I had the privilege of using NTDS as a command and control tool. Its effectiveness is such that I consider the evolution of this system to represent the single greatest step forward in tactical direction since the invention of radar. The equipment reliability is of a very high order, the 'down? time over the past few years being measured in minutes instead of hours and days.?
Hughes Aircraft Company can look with pride at its contribution to the U.S. Navy forces afloat and the technical edge provided to many of the world's navies. The Surface Ship Systems Division represents a proud heritage.
Author?s Note: Malcolm Macaulay, senior engineer in Advanced Large Screen Display development in Division 1D, contributed to the article. He worked on the original system checkout in 1958. Division 1F senior engineer Bill McNally is the son of Cdr. Irving McNally who established the original system requirements.
Posted by Craig Hubbard
Jan 09 2006 04:46:01:000PM