Defense Technology International - December 2007 - (Page 42)

DATA LINKS AIRBORNE U.S. AIR FORCE be carried on a Global Hawk UAV—the WB-57 version weighs 6,000 lb. A 2006 USAF presentation shows BACN Spiral 3 on a Gulfstream, with Spiral 4 tested on a Global Hawk in 2010 and an internal system in 2012. The deployment of such a system, however, will depend on the availability of Global Hawk assets, as well as the ability of developers to halve the system’s bulk. This raises questions. Unless they are operating as part of a coalition with the U.S., and the U.S. has gateway systems in the theater, export JSF operators will be conﬁned to the slow and questionably stealthy Link 16. It also means that the F-22 and F-35 need support from a new, and so far not fully-funded platform to connect at optimal speed to a network. As the Pentagon’s Fiscal 2008 budget request notes, “the type of networking projected to meet . . . tactical requirements is not supported by network theory, network design nor analysis tools.” Network-centric is a longer and harder road than most people think. I F-22 is being cleared to carry GBU-39 Small-Diameter Bombs to attack SAMs, but still needs a data link for integration into a defensesuppression system. Cold War-era RB-57F is the only high-altitude aircraft able to carry prototype BACN gear, which should allow the F-35 and F-22 to communicate at high speed with other users. NASA RADAR MESSAGING Not relying on stealth for survival makes it easier to communicate, something Raytheon and L-3 Communications have exploited in tests that use the F/A-18E/F Super Hornet’s new AESA radar as a communications device. The starting point is the radar’s ability to interleave operating modes, and even to divide itself into sub-apertures so it can carry out multiple tasks. The radar is capable of gathering information, such as SAR maps— 8-megabyte ﬁles that are too large to send over Link 16. It is also important that the Super Hornet has a digital radar-warning receiver (RWR). On board the Super Hornet, the crew selects a freeze-framed image from a 42 SAR map—the ability to record and edit SAR imagery on board is also important. L-3 provides hardware to convert the radar image to a format that’s transmitted by the radar. An 8-megabyte map can be transmitted in 80 millisec., faster than any other airborne link, and Raytheon says the speed can be increased with new compression algorithms. Initial tests were radar-to-radar, but this might not work if the sending and receiving aircraft were not in the right geometry relative to each other. Enter the digital RWR, which a Raytheon executive says is “dramatically more sensitive and receives well off the side lobes.” The receiver aircraft can ﬂy in any direction and receive, as long as it is within an arc centered on the transmitter aircraft’s nose. Raytheon, L-3 and Boeing won a USAF contract in June to develop standards and protocols for a radar common data link (RCDL) for the Super Hornet and AESA-equipped F-15s. Now, the main application is likely to be non-traditional ISR. For example, Raytheon points out that data linkequipped ﬁghters could gather SAR and ground-moving, target-indication data in “shadow” areas, hidden by terrain from stand-off radar surveillance assets. While the F-35 waits for a satcoms link, this capability has been developed for the Super Hornet through the EA-18G Growler electronic attack variant, which incorporates the receive-only, multi-mission, advanced tactical terminal. Going one better, Israel’s F-16I carries a two-way Ku-band satellite link, the IAI-Elta EL/K-1891, in a dorsal radome. I www.aviationweek.com/dti DEFENSE TECHNOLOGY INTERNATIONAL DECEMBER 2007 http://www.aviationweek.com/dti

Table of Contents Feed for the Digital Edition of Defense Technology International - December 2007

Defense Technology International - December 2007 Contents Around the World Science Watch Tech Watch BrahMos: Ramjet Ship Killer r-e-s-p-e-c-t Deja Vu Trump Card Dubai Demos Agile Helos Joint Force Online Charge UGVs Creep, Crawl to Victory Sweet Ride Fast, Lethal Ship Defense Networking Stealth: Why Raptors Can't Talk The Net Cutting Edge First Person In Review Insight

Defense Technology International - December 2007

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