JSF - a key sensor and shooter in the networked air force

There's more to air combat capability than just speed, thrust, payload and wing loading. Air combat in the 21st century is all about systems and networks of systems - the old rules of thumb about what gives you a winning edge are obsolete.

In October 2002, Australia joined the System Development and Demonstration (SDD) phase of the Joint Strike Fighter project. At the time the Australian Government also reaffirmed that the JSF was expected to replace the air combat capabilities currently provided by the F-111 and F/A-18.

Defence and the New Air Combat Capability (NACC) project office are currently conducting a three-year detailed analysis/risk mitigation phase to confirm the JSF meets the RAAF's future air combat requirements. While we are only half-way through the detailed analysis, the more we see of JSF the more we like.

The JSF is a true fifth generation multi-role stealth fighter. With its combination of advanced sensors, sophisticated data fusion, multi-band communications systems, and precision weapons capabilities, the JSF will be a key sensor and shooter in the networked Air Force.

While there have been some arguments raised that the F/A-22 also offers similar or even better capabilities in these areas, the bottom line is that it is still unclear whether it will provide a true multi-role capability and at approximately US$150 million it is imply unaffordable. One hundred F/A-22s would lead to a total project cost at least three times the budget currently available with no guarantee of a robust strike capability.

A key feature of the JSF, and certainly one of the features that discriminates it from its competitors, is its Low Observability (LO) or stealth characteristics. While stealth does not offer invisibility, it does offer significant advantages over non stealthy aircraft in both the air-to-air and air-to-ground environments.

In the air-to-ground environment it significantly increases access to targets whilst remaining undetected. In the air-to-air environment it provides first look, first shoot, first kill capability over non-stealthy aircraft.

At the heart of the JSF's sensor suite is its Active Electronically Scanned Array (AESA) radar that provides both air-to-air and air-to-ground target detection.

In air-to-air operation the electronic array provides for rapid, multi-volume search and long range detection of aircraft and low radar cross section (RCS) targets such as cruise missiles. It will provide the capability for the JSF to simultaneously engage up to six air targets with AMRAAM missiles, a significant jump over current F/A-18 capabilities.

The AESA radar will also be extremely capable in air-to-ground operations.

The synthetic aperture radar mode provides high quality imagery for targeting, identification and attack. Overlaid on the synthetic aperture image is the ability to detect moving targets with its Ground Moving Target Indicator (GMTI) mode.

For maritime targets, an inverse synthetic aperture radar (ISAR) mode will provide for ship classification. In the passive mode, the multi-function array also provides electronic support capability and precision direction finding to locate radar targets. The array also provides electronic attack (EA) capability against air and ground threats.

Importantly, most modes can be conducted nearly simultaneously whilst conducting air target search and track.

In terms of synthetic aperture radar, imagery resolution is generally restricted by limited processing capacity The processing capacity of the JSF will provide a significant increase in resolution, even in Low Resolution mode, over what can be achieved with current fighter aircraft radar systems.

In medium resolution mode the improvement is even greater, but it is in the High Resolution mode that the threshold jump in capability is achieved. And the improvement is not just in resolution of the image - the image can be overlaid on precise geographic coordinates so that GPS-guided weapons [Such as JDAM, Enhanced Paveway II and Small Diameter Bomb - Ed] can be targeted directly.

It therefore also provides an inherent all-weather reconnaissance capability at considerable stand-off distance.

If you were to compare the JSF's High Resolution SAR image with the Forward Looking Infrared Image generated by the JSF's Electro-Optical Targeting System (EOTS), the photo-like quality of the sensor would be apparent.

The big advantage of the SAR image, however, is that it is available day and night in all weather and from a considerable stand-off range. The EOTS does, however, provide higher resolution when it can be used and represents another inherent reconnaissance capability. The JSF's EOTS also provides:

* Long range infra-red search and track

* Long range detection of ground targets

* Laser range-finder

* Laser target designation

As mentioned earlier, the radar also offers a Ground Moving Target Indication (GMTI) capability, overlaid on the SAR
Unique to the JSF is a Distributed Aperture System (DAS) comprising 6 electro-optic sensors around the aircraft to provide full spherical coverage.
These sensors provide:

* Passive tracking of flight members

* Short range air-to-air missile targeting

* Defensive infra-red search and track against enemy fighters

* Detection and targeting of ground targets

* Detection of threat air-to-air and surface-to-air missiles

The images from the sensors are seamlessly 'stitched' together to provide the full spherical coverage for viewing on the helmet-mounted display. The DAS provides the JSF pilot with the ability to effectively look 'through' the aircraft, removing any blind spots.

The JSF also has an extensive Electronic Support (ES) capability, providing full spherical Radar Warning Receiver (RWR) coverage with Precision Direction Finding (PDF) capability in the forward sector for targeting purposes.

As important as individual sensors are, however, the real leap in capability comes from fusion of data from the individual sensors. This includes:

* Spherical RWR coverage to detect radar threats

* Passive ES from the radar array

* Long range detection of targets using the DAS or EOTS

* Active radar detection of targets - air, land and maritime

* Close range warning of threats using the DAS

And fusion of data goes beyond just the on-board sensors. To achieve a fully fused
* Tier 1 develops tracks based on the full range of on-board sensors

* Tier 2 brings together the tracks from other JSFs in a flight based on the high capacity Inter-Flight Data Link

* Tier 3 adds tracks from off-board sensors such as AEW&C, AWD and broadcast intelligence information

The JSF provides the ability to choose the sources of information to ensure the best possible assessment of the situation. The real strength of the data fusion capability is that it provides the pilot with unprecedented situational awareness - a key determinant of combat success.

But to achieve all this data fusion the JSF needs to be able to share data with a range of off-board assets. Key amongst these will be:

* The high capacity inter/intra-flight data-link to allow a flight of JSFs to act as a fully fused team

* Link 16 allows sharing of data with other air and surface assets

* Satellite communications provides for beyond line of sight communications. (The JSF is the first fighter aircraft to have satellite transmit and receive capability)

* Software-driven Joint Tactical Radio System (JTRS), primarily for communications with ground forces

* The Prognostics and Health Management data-link provides for integration with the JSF's Logistics system.

The airborne architecture is fully evolvable - essentially software-driven. As long as antennas and transmitters are available to cover the appropriate frequency band, the necessary waveforms can be generated or processed.

That means as new communication systems or standards come along the JSF can be reprogrammed to meet the new need without changing hardware. So what this leads to is three levels of JSF operations:

* Fully autonomous operation as a single JSF aircraft

* Integrated mission capabilities with a formation of JSF aircraft

* Integrated Network Warfare Capabilities when networked with the full range of ADF assets.

As we've seen, the JSF has a lot to offer as a 'sensor'. But it also has a lot to offer as a 'shooter'.

The JSF, with 10 weapons stations, can actually carry more weapons than the F-111. The four internal weapons stations can carry, for example, two 2,000lb-class air-to-surface weapons while at the same time carrying two AMRAAMs. Alternatively eight small diameter bombs can be carried internally.

The six external weapons stations allow for carriage of additional air-to-air and air-to-ground weapons or fuel tanks when being stealthy is not a major requirement. The inboard wing pylons are stressed to carry air-to-ground weapons weighing up to 5,000 lbs.

The range of weapons available is also extensive, both for internal and external carriage. It includes:

* AIM-9X and ASRAAM

* AMRAAM

* Small Diameter Bomb

* JDAM

* JASSM

* Joint Common Missile/Brimstone

* JSOW

Not all of these weapons will be cleared for Block 3 delivery but will be progressively cleared in the future upgrade blocks. The RAAF is currently looking at two options for standoff anti-ship capability - a maritime version of Lockheed Martin's Joint Air-Surface Standoff Missile (JASSM) and the Norwegian-designed Kongsberg NSM (Naval Strike Missile).

While we tend to think of 'shooters' using a hard-kill approach, the JSF also offers a soft-kill capability - as a jammer, in other words - with the Electronic Attack (EA) capability of the AESA radar. This opens up new capabilities for the RAAF and ADF.

The JSF will change the way we do things - we will be working with new capabilities that we've never had - LO and EA are just two and we will need to work them together. Current Standoff Electronic Attack operations relay on Standoff platforms and this is becoming problematic because of:

* Longer-range air defence missiles

* Improving threat radars

* Line of Sight constraints

* Lack of terminal area support

* Reliance on LDHD assets

* Lack of synergy (logs & ops).

For the future, the combination of Low Observability plus Electronic Attack allows for Penetrating EA operations. This will allow for a robust networked force package with fewer specialized assets.

The JSF's EA capabilities will enable:

* Laser Pointer as well as Floodlight EA modes

* Focused energy in space, frequency and time, and

* Will support weapons already launched all the way to the target.

Putting all these capabilities together we can illustrate how four JSFs would operate in a future deep attack scenario.

One JSF would receive tasking via SATCOM and share this data with its flight members through the inflight data link. Two JSFs could then begin a Combat Air Patrol (CAP) passively seeking electronic emissions from enemy defences, while one JSF from the other pair emits using its radar to build an initial low resolution SAR
The emitting JSF would continue to build a higher definition SAR
Note that all flight members are aware of the others' activities and actions through shared information on the data link.

The JSF on CAP would provide high gain electronic jamming to protect other flight members; the JSF building the SAR
After weapon impact one of the JSFs would capture post attack battle damage imagery using the SAR and this would then be linked back through the command chain.

Another side of these capabilities can also be illustrated in a stylised defensive counter air scenario involving four JSFs operating passively on CAP in a dispersed formation, sharing information through the inter flight data link and obtaining a detailed and regularly updated air
When the AEW&C detects adversary aircraft it would pass the track information to the JSF via data link; as the range between the JSFs and adversary aircraft decreases the JSFs would employ PDF High Gain ES techniques and share information through data link to build on their tactical awareness.

While still maintaining a passive, and hopefully undetected, approach the formation would manoeuvre to place two aircraft wide on the flanks of the incoming enemy force, while one of the remaining pair of JSFs lights up its radar to prepare for a BVR shot. The track and identification information it derives is passed to the two flanking aircraft via data link and these, at closer range, would engage the incoming 'bogeys' with a high kill probability.

Because of its sensor and shooter capabilities and its networking ability JSF can act as:

* A sensor - passing target information to another JSF, an Air Warfare Destroyer or perhaps special forces who can use the radar information

* A shooter - receiving information from an AEW&C, AWD or perhaps special forces who have identified and designated a target

* Both sensor and shooter when operating autonomously.

The JSF's combination of advanced sensors, sophisticated data fusion, multi-band communications systems, and precision weapon capabilities will allow it to be a key sensor and shooter in the networked Air Force of the future. This, combined with its stealth features, will make it a highly lethal and survivable air combat capability for Australia. There is still a long way to go to deliver these advanced capabilities but the JSF represents the opportunity for a huge jump in capability for the RAAF.

Air Commodore John Harvey is the Director General New Air Combat Capability, responsible for Project Air 6000. This is an edited version of a presentation he gave to the Defence Watch Seminar in Canberra in May this year.

By Air Commodore John Harvey, Canberra