AC-130J Ghostrider Could Get Huge Upgrade From AESA Radar

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AC-130J Ghostrider Could Get Huge Upgrade From AESA Radar

An active electronically scanned array radar would allow AC-130Js to independently engage targets in any weather and at greater distances.

byJoseph Trevithick, Tyler Rogoway| UPDATED May 15, 2023 7:47 PM EDT

 

The U.S. Air Force plans to test an AC-130J Ghostrider gunship equipped with an active electronically scanned array (AESA) radar. Adding an AESA would give these aircraft a valuable tool for spotting, tracking, and engaging targets, especially in bad weather and at extended ranges. The radar could perform more general intelligence-gathering and provide improved situational awareness, along with other functions, as well.

The forthcoming AC-130 AESA testing was highlighted during a briefing last week by members of U.S. Special Operations Command's (SOCOM) Program Executive Office for Fixed Wing aircraft (PEO-FW), which The War Zone, among others, attended. That event was held as part of an annual special operations-focused conference now called SOF Week.

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An AC-130J Ghostrider. USAF

"We have a tech demo coming up, where we've got a Cooperative Research and Development Agreement [CRADA] to do an AESA radar on an AC-130 gunship," one of the representatives from PEO-FW said. The testing will help SOCOM "see what capabilities that can help us bring to the fight."

A CRADA is a process wherein the U.S. military partners with a private company or research institution on a particular project, but without a traditional contract award. CRADAs typically involve various degrees of sharing of resources and the results of any testing in lieu of a typical exchange of funds.

What specific AESA SOCOM plans to test on the AC-130J is not currently known. This is, of course, not the first time SOCOM, together with the Air Force, has looked into equipped AC-130s with a radar of this general type.

In 2015, SOCOM revealed that it had been testing the AN/ASQ-236 Dragon's Eye radar pod on its gunships as part of an earlier CRADA. The pod was flight tested on at least one AC-130 mounted on a pylon under the right wing.

An AN/ASQ-236 Dragon's Eye radar pod under the wing of an AC-130 gunship. USAF

The AN/ASQ-236 features an AESA radar that is capable of rotating left and right along the pod's center axis. It has a synthetic aperture functionality that is said to be sensitive enough to generate near photo-quality radar maps and to spot shallow-buried objects, such as improvised explosive devices and individuals in dugouts. It also has a GMTI capability that is reportedly able to track moving vehicles and ships. The complete pod has the ability to geo-locate targets that the radar spots and systems required to keep everything cool.

SOCOM and the Air Force ultimately determined Dragon's Eye, at least in the form available at the time, to be unsuitable for use on the AC-130. The exact reasons for this remain unclear.

“The AC-130J does not have a sensor system that enables adverse weather engagements by detecting and tracking targets obscured by weather, smoke and haze or obscurants,” according to the Pentagon's Office of the Director of Operational Test and Evaluation's annual report for the 2016 Fiscal Year. “Earlier efforts to integrate an AN/ASQ-236 radar pod were unsuccessful.”

Dragon's Eye is currently primarily carried by Air Force F-15E Strike Eagles and F-16C/D Viper combat jets, though it has also been tested on other platforms, in addition to the AC-130, like the B-52 bomber.

A new variant or derivative of Dragon's Eye, or another podded AESA radar, mounted under the wing or using an add-on pylon installed on the AC-130J's right-side rear paratrooper doors might still be an option. The left-side door on the Ghostrider is already taken up with the aircraft's 105mm howitzer.

An example of a modified C-130 rear paratrooper door with an add-on pylon with a pod attached. via ThinkDefence.co.uk

Other podded AESA radars with still significant synthetic aperture and/or GMTI functionality do exist, including ones small enough to be mounted on drones. Some of these, such as the AN/ZPY-5 Vehicle and Dismount Exploitation Radar (VADER) and IMSAR NSP-series, are in U.S. military service now or have otherwise been evaluated already by SOCOM.

A radar using some other kind of mounting arrangement could be another possibility. For example, earlier this year, Marshall Aerospace in the United Kingdom unveiled a roll-on/roll-off palletized AESA radar system for C-130-series aircraft that uses conformal antennas installed in modified rear paratrooper doors.

A portion of Marshall Aerospace's palletized radar system for use on C-130-series aircraft. Marshall Aerospace

A number of older AC-130 variants had a sensor called Black Crow, which included an antenna inside a dome, installed on the left side of the 'cheek' area. Black Crow was designed to pick up electrical impulses generated by the spark plugs in trucks and other vehicles with internal combustion engines. This could be an ideal location for a side-facing AESA radar on the AC-130J, but it would come at an aerodynamic penalty, which really is nothing new for the bristling AC-130.

 

The same sensor installation arrangement stuck around long after the war ended. USAF

Regardless, compared to older mechanically-scanned types, AESA radars offer significant benefits. This includes being typically able to spot objects of interest, even those with low radar cross-sections, faster and do so with greater precision and fidelity. AESAs also generally have very fast scanning and return rates, and can perform multiple functions near-simultaneously.

In addition, AESAs have improved resistance to radiofrequency jamming. With no need for a mechanical assembly to steer the antenna, systems that can often be very complex in their own right, radars of this type are more reliable, too.

The improved capabilities AESAs would offer at their core have further benefits when combined with other kinds of functionality, including synthetic aperture mapping and imaging and ground-moving target indicator (GMTI) modes.

The feed from an AN/ZPY-5 VADER radar as an example of AESA GMTI functionality overlaid on top of a topographical map. DHS

Compared to the electro-optical and infrared full-motion video cameras already found on the Air Force's AC-130Js, an AESA radar is also capable of functioning in any weather and of 'seeing' through dense smoke, dust, and other obscurants. This includes modern chemical smokescreens specifically developed to defeat optical and infrared sensors.

The Ghostrider's existing cameras do have various low-light-level and thermal capabilities, though an AESA can also work at night just the same as day. AESAs have the additional benefit of being immune to optical dazzlers and infrared interference, which are an increasing issue on the battlefield, as well.

Altogether, a modern AESA with a good field of view could be particularly useful on an AC-130 gunship for targeting and more general intelligence, surveillance, and reconnaissance (ISR). But depending on how deeply integrated such a system would become into the AC-130J's complex mission systems suite, it could prove even more valuable.

The AESA radar would also spot targets for further investigation using the AC-130J's other sensors, or vice versa. This, in turn, could improve the ability of the aircraft's crew to positively identify targets rapidly, including in very bad weather and in dense urban or otherwise complex environments. Paired with advanced software algorithms and advanced back-end processing, these systems can automatically spot targets or patterns of interest and alert operators as to their proposed classification and location.

Once targets are found and identified, an AESA radar can be very valuable for helping AC-130J crews actually engage them, especially at stand-off ranges. As it stands now, Ghostriders rely heavily on off-board platforms to make the most of their longer-range munitions, such as the GBU-39/B Small Diameter Bomb (SDB) and its laser-guided variant that can hit moving targets, although the latter needs something nearby lasing the target directly to do so. The standard SDB, which can only be used against fixed threats, has a stated maximum range of more than 40 nautical miles.

The Ghostrider is already in line to receive the much-improved GBU-53/B StormBreaker, which has a new multi-mode seeker system that gives it the ability to engage moving targets over its entire range without laser designation occuring. You can read all about StormBreaker here. A true self-contained ability to engage moving targets at stand-off ranges in any weather, which the AC-130J does not have now, would be a major capability boost by itself. An AESA would make this possible by providing the initial targeting and datalink updates for StormBreaker.

The AC-130J's need for longer-range target acquisition capabilities is only set to increase as its arsenal gains ever more capable precision-guided munitions able to hit targets further and further away. During SOF Week 2023, SOCOM's PEO-FW also highlighted interest specifically in adding new stand-off strike capabilities through the acquisition of small and miniature "cruise missiles" for use on the Ghostrider and other aircraft.

An AC-130J in the anechoic chamber at Edwards AFB. (USAF)

"Miniature" in this instance would be something small enough to fit inside a standardized Common Launch Tube (CLT). "Small" refers to larger designs that would be launched via a more traditional pylon or something like the Air Force's Rapid Dragon palletized munitions system. Smaller and lower-cost air-to-surface munitions with stand-in, if not stand-off range have been of interest to SOCOM and the Air Force for some years now.

An AESA radar could be used to help direct the AC-130J's 30mm automatic cannon and 105mm howitzer during shorter-range engagements, too. This would give the gunships another way to engage threats with those weapons even through cloud cover, smoke, or heavy dust.

An AC-130J Ghostrider with its 30mm automatic cannon, at left, and its 105mm howizter, at right, visible. USAF

Advanced mission systems, potentially leveraging artificial intelligence and machine learning technology, could be used to fuse data from multiple sensors on the Ghostrider in various ways to further improve its overall targeting and ISR capabilities. The aforementioned help in automating target recognition and categorization could be especially useful for gunship crews. SOCOM is already exploring the possibility of adding artificial intelligence-driven targeting and other capabilities onto the AC-130J, as well as other aircraft, in the future.

Depending on the type of AESA and its capabilities, how it is mounted, and especially how deeply it is integrated into the AC-130J's mission systems, it could potentially be used in a secondary role to provide additional threat warning, electronic attack, and general situational awareness. Such capabilities could be further integrated into the AC-130J's already extensive and still-expanding electronic warfare systems. Beyond helping to detect incoming threats along with other onboard systems, it could be used as a very powerful electronic warfare emitter, helping to protect the AC-130J but also working in an offensive EW capacity as a secondary capability set.

Improving the AC-130J's ability to spot and track targets at extended ranges, as well as its intelligence-gathering, situational awareness, and even self-protection capabilities, could be especially important in the coming years. For decades now, gunships like the Ghostrider have been primarily employed in counter-terrorism and other lower-end combat operations in largely permissive airspace.

ith the U.S. military's ongoing shift in focus to preparing for higher-end fights, with a specific eye toward a potential conflict with China in the Pacific, there are growing questions about what the future might hold for gunships like the AC-130, in general. One possibility, which would be further enabled by the addition of an AESA radar, could be the more localized use of the AC-130J for force protection missions of austere outposts — such as on islands — on the outer edges of the enemy's anti-access capabilities.

Being able to detect anything of interest for many miles around an island and leveraging its high-end communications and self-protection suites in the process, an AC-130 could provide an inner layer of awareness for U.S. forces in remote locales. Its ability to kill any of those targets and at a distance gives it all that much more relevance.

Once again, it all depends on how this capability evolves. To start, if just a basic GMTI and SAR functionality can be had, that would be a big leap in itself. But more robust abilities could soon follow.

So, while the results of this new round of testing of an AESA on the AC-130J remain to be seen, adding this kind of radar to the Ghostrider would make great sense. Coupled with other potential upgrades and new weaponry, the radar could be an important addition to help ensure the relevance of these gunships in future higher-end scenarios.