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US Navy Mulls NGJ Architecture Choice
This article first appeared in Aviation Week & Space Technology.
The U.S. Navy is poised to make difficult decisions regarding its primary airborne electronic attack initiative, with a goal of finding the right balance between performance and acceptable program risk.
The service is committed to making the Next-Generation Jammer (NGJ) the backbone of its future electronic attack capabilities as it prepares to replace ALQ‑99 pods used today on the EA-6B Prowler and EA-18G Growler.The focus is now shifting to fully defining what the new system should look like. The decision has big implications for industry, with Northrop Grumman, BAE Systems, Boeing and Raytheon already working on the early development activities. Other bidders also could participate.
Part of the operational envelope that NGJ will open for naval aviation involves sophisticated airborne electronic attacks (AEA), nonkinetic standoff weapons and the penetration of integrated command-and-control networks. The U.S. Air Force demonstrated the capability by aiming a data beam packed with algorithms into the antennas of an air defense network operating on the Nellis Test Ranges in Nevada. Since that time, the task has been to reduce AEA packages to a size that can be carried by tactical aircraft.
What the NGJ architecture should look like is one key question the Navy must answer. With the low-band jammer to be packaged into a center-line carrier pod, the current conundrum is to decide whether jamming of other radar bands should be housed in only two other pods -- one under each wing -- or whether a four-pod setup would make more sense. Although the three-pod arrangement (including the centerline low-band jammer) would leave space for other payloads, the Navy is worried about program risk. As Capt. John Green, the Navy’s AEA program manager, points out: "We believe the three-pod solution is much riskier."
An architecture decision has to be made in the next 6-8 months to properly spell out the bidders’ requirements for the next round of technology development. The Navy plans to award two development contracts that will run two years. That phase is expected to include a flight evaluation to help choose the winning provider for the NGJ. Nominally, the Navy hopes to field the jamming system around 2018.
The Navy has drafted exacting requirements for the jammer, including a far higher effective radiated power, polarization control and a cleaner spectral output to avoid jamming friendly systems. The service also wants enhanced modularity so the system can be upgraded. A few years after it is first fielded, the system will already look very different, Green told an IQPC airborne electronic warfare conference in London.
Every antenna on the battlefield will be a target, particularly those associated with enemy air defenses, say industry officials with insight into cross-service AEA programs. However, other Navy and industry specialists note that new radar systems -- based on active, electronically scanned array (AESA) technology -- have triple the detection ranges of mechanically scanned radars and can locate stealthy aircraft and missiles. U.S. and Israeli planners indicate they will continue to use nonstealthy aircraft but equipped with long-range jamming tools to thwart enemy air defenses. Unmanned aircraft would be used to penetrate closer to such threat systems.
"NGJ is a highly complex development program with lots of moving parts," says Dennis Hayden, director of business development for Northrop Grumman’s information operations and electronic attack division. "The Navy is not only keeping industry working intensely on the multiple-configuration possibilities for the EA-18G, but they also have us addressing the [Marine Corps’] F-35 requirements that will add an updated receiver system and mission computer as well as single-seat operations to the mix -- all in a similar timeframe."
NGJ is expected to create a marriage of various AESA antenna designs (to increase coverage to 360 deg. around an aircraft) that are controlled by easily updated and replaceable software packages. The Navy has asked industry to assemble its best ideas for the NGJ and offer them as a catalog of concepts that are achievable in the near term. Power and cooling, not electronic or network attack capabilities, have been identified and are the NGJ’s biggest challenges.
"The Navy has asked us to look at anything that will maximize the performance of NGJ and minimize program risk," Hayden says. "That’s why we’re spending a lot of time and [company] money on modeling and simulation."
The Office of Naval Research also is spending about $28 million on the Next-Generation AEA program to mature future technologies for the NGJ. Although Green would not specify in what areas the work is underway, he notes that funding has already been adjusted -- in some cases, with more money going to promising technologies and withdrawn from less promising areas. These activities will provide the basis of technology insertion once the NGJ is fielded.
A key feature of the NGJ is slated to be its power generation; the Navy wants to eliminate the ram air turbine (RAT) used for the ALQ-99 to improve the field of view, so the new pod is to feature an internal, ducted RAT.
Operationally, the combination of Growler and NGJ-standoff jamming capabilities is expected to revitalize the value of stealth aircraft in penetrating the new AESA-improved, ground-based, air defense systems. Because of the geographic proliferation of advanced surface-to-air missile systems, part of the NGJ challenge is to address all the threats with fewer transmitters and aircraft than are required today.
Several issues remain to be resolved, however, including the exact frequency allocation between the different jamming devices. The Navy may also have pods with several AESAs to be able to properly jam multiple radar or communications sites. One of the NGJ’s features is the planned ability to defeat bistatic and multistatic radars.
To minimize cost, the service is likely to field the NGJ in increments. But the exact plan has yet to be defined. The low-band jammer version will probably come later, since its development is relatively new. That also means, though, that the Navy could still be facing upgrade and sustainment bills for the ALQ-99 even as development and production funding for the NGJ would be ramping up.
Apart from the Navy, the Marines have set their sights on the NGJ. "We are heavily reliant on the success of the Next-Generation Jammer" for use on the Lockheed Martin F-35 Joint Strike Fighter and for advanced electronic warfare payloads for unmanned aircraft, says Lt. Col. Shawn Cunningham, aviation officer for the Marine Air Ground Task Force.
The Marines plan to equip their Group 4 fixed-wing unmanned aircraft -- intended to replace the Shadow 200 -- with intelligence collection and standoff jamming capabilities. The system, due to be fielded around 2016-18, would initially carry the ALQ-99 pod and, later, an NGJ version. Operationally, an unmanned aircraft with NGJ would likely be assigned different frequency bands to jam than an F-35.
For the unmanned systems applications, military officials are looking for software reprogrammability, allowing them to modify jamming frequencies in flight. The U.S. Army is trying to validate some of that capability with its communications electronic attack with surveillance and reconnaissance (Ceasar) development effort aimed for use on Shadow 200s and eventually on the Sky Warrior unmanned aerial system.
Photo credit: DOD