The US Navy is testing its own signals-intelligence system.


AFTER YEARS OF FRUSTRATION, the US Navy is ready to introduce its own intelligence-gathering system, including equipment which, one day, could serve all US military forces.

The USN is committed to maintaining 12 aircraft carriers into the 21st century, developing a next-generation large-deck "flat-top" and shifting its doctrine away from the deep-water Soviet threat to one of localised conflicts (Flight International, 20-26 March, P35). Consequently, the Battle Group Passive Horizon Extension System (BGPHES), a real-time signals-intelligence system designed to extend the "horizon" for battle group and joint task force commanders, is assuming greater significance.

While a long-range signals-monitoring device developed by Raytheon's E-Systems Falls Church division will be used to shield warships from attack, work is continuing to allow others to contribute to (and benefit from) the long-range security net which will be the BGPHES.

For the USN, horizon extension is provided by a remotely controlled airborne sensor, aboard the Lockheed Martin ES-3A Shadow. The RS-6BN payload borrows from the US Air Force's RS-6B sensor installed on intelligence-gathering aircraft. The BGPHES surface terminal is coupled to the ES-3A by the Loral-produced secure common high-band-width datalink.

The shipboard-operator terminals, which are used to control and process the signals collected by the airborne sensor, will be installed on 23 USN warships, the large-deck amphibious assault ships and all 12 aircraft carriers.

An S-3B Viking variant, the Shadow replaces the Douglas EA-3 Skywarrior. Sixteen aircraft are based at Cecil Field, Florida, and North Island, California.

The ES-3As are deployed in rotation as two-aircraft detachments aboard carriers. The aircraft has a similar crew arrangement to that of the four-seat S-3B, except that two electronic-warfare operators handle the electronic-surveillance equipment in the rear of the Shadow, with an electronic-warfare combat coordinator alongside the pilot, in the front.

The S-3 entered naval service 20 years ago, but the USN wants to operate it until at least 2015. The service has initiated a service-life assessment programme to determine the S-3's remaining fatigue life. A follow-on service-life-extension programme may follow.


Although the BGPHES concept was hatched in the late 1970s, false starts delayed aggressive research and development until 1985. After more setbacks, it was decided in December 1993 to adopt software from the US Air Force's ground-based terminal. Meanwhile, E-Systems began work on shrinking the BGPHES from a 16-rack to a two-console system.

The firm finished an engineering-development start in August 1994 and, between October 1994 and March 1995, a land-based BGPHES demonstration was completed, using an ES-3A, at NAS Patuxent River, in Maryland.

The idea grew to make the BGPHES a joint reconnaissance system, offering Joint Task Force commanders real-time intelligence. Between 3 and 7 April 1995, an interoperability exercise was successfully conducted at Patuxent River, involving USN and USAF terminals and an RS-6B-equipped Lockheed Martin U-2.

Along with the system's ability to be operated with the U-2, the US Army's Guardrail system will incorporate the BGPHES surface terminal into its ground processing, to achieve similar joint capabilities. The US Marine Corps is also interested in the BGPHES, and unmanned air vehicles could be operated with the system.

In August 1995, the BGPHES was installed on the USS John F Kennedy. A one-week technical evaluation was conducted in January 1996 and it passed muster. In February, a second interoperability demonstration was completed in Florida, and the critical operational evaluation is due this month.

System refinements continue to be made, and the ES-3As are already operational, albeit without BGPHES capability. The USN will acquire ten RS-6BN payloads, to be shared among the 16 ES-3As. The BGPHES will also be able to use shipboard antennae to monitor the area around equipped warships.

The BGPHES will move from engineering and manufacturing development to production, with the Milestone 3 decision due in June. Although developed by E-Systems, the plan is for the USN to build the BGPHES in-house, with initial operational capability set for 1998.

In the future, the BGPHES may evolve into a "joint" asset offering real-time critical intelligence data to all of the US military services. Considering the Pentagon's track record in developing shared weapons, the BGPHES could become a model for future weapons developments.

Source: Flight International