Paris Air Show

Thales helps extend Rafale reach

 - June 8, 2009, 5:21 AM

Thales is engineering a series of upgrades to the sensor systems aboard France’s Rafale that will be incorporated in the next batch of aircraft for the French armed forces and should enhance Dassault’s chances in current fighter procurements contests in Brazil, India and Switzerland.

Equipment from Thales accounts for around 30 percent of the airplane’s cost, officials said at the company’s Elancourt site near Paris last month. The list includes cockpit displays and the main computer, electrical generation, radios and tactical datalink. But the main upgrade focus is on the sensor suite of radar, built-in and podded optronic systems and electronic warfare.

The initial F1 air-to-air version of the Rafale was delivered to the French navy in 2001. Subsequent F2 multi-role and F3 omni-role models have introduced comprehensive air-to-ground and air- to-sea capabilities, and the pending F4 will add the latest sensor upgrades. A sensor road map agreed with the French defense procurement agency calls for aircraft with the new-generation sensors to be delivered to the air force and navy by 2012.

Most significant is an active electronically scanned array (AESA) antenna for the Rafale’s RBE2 radar. Based on work stretching back to the early 1990s, this involves a new front end with several hundred transmit/receive modules: by controlling each module individually, the antenna can steer the radar beam extremely rapidly and track multiple targets simultaneously in all directions.

“A mechanically scanned antenna loses targets once two aircraft in a formation of four split away,” said Rafale program manager Jean-Noel Stock. “But with electronic scanning you can continue to track the split targets even if they are outside the radar’s search pattern.”

The AESA antenna also increases range by more than 50 percent, improves detection of targets with small radar cross sections and provides better resolution in ground mapping, he said. And in air-to-ground mode the radar technology supports simultaneous terrain following and high-resolution imaging for target identification and targeting.

The capability boost comes at a higher unit price, but lifecycle costs should be lower, Stock said. “Because there is no single transmitter you can lose tens of emitters before the antenna needs to be repaired, so maintenance costs will be much lower,” he explained.

The final concept demonstration flight of the active antenna took place in April, and it was shown to Switzerland last October and Brazil in March. United Arab Emirates F-16 pilots have also tried it and are said to have been “very happy” with its performance. Now Thales is due to produce two series radars as precursors to production for the fourth batch of French armed forces Rafales, which is expected to run to around 60 aircraft. “The demonstrator showed the technology was available,” Stock commented. “The next step is to optimize maintainability, producibility and cost.”

The active radar is complemented by passive infrared and TV sensors and a laser rangefinder in the frontal sector optronics system. This provides detailed images of targets rather than just a dot on a radar screen, said program manager Marc Brousse, and has found new applications during operations in Afghanistan.

As well as being used routinely to scan ground convoy routes for ambushes, he said, it has proved an aid to aerial refueling. “Pilots can see the tanker further away, confirm that it is a tanker, see how many other fighters are waiting and plan a route to it without stress,” explained Stock.

The Rafale’s Spectra electronic warfare suite, meanwhile, detects radar and jamming signals and warns of laser illumination or missile warning. Consisting of sensors, receivers and emitters distributed around the airframe, it comes with a threat library generation system so that customers can develop their own libraries and add new threats specific to their operating environment.

Enhanced Pods
The built-in systems can be supplemented by mission-specific podded equipment. The new RECO NG/Areos airborne reconnaissance electro-optical system, though, is more than just a new pod, said Serge Larroque, reconnaissance product line manager. Along with the pod, it includes a mission-planning system, ground data terminal and ground-image exploitation system to form a complete imagery intelligence system.

The product of a nine-year development program, the Areos pod combines visible and infrared focal plane arrays, each with two wide and two narrow fields of view for short-, medium- and long-range reconnaissance with an infrared linescanner for low-level, high-speed panoramic acquisition. The onboard software alone took five years to develop and contains 1.2 million lines of image collection and mission management code.

Thales is supplying 20 copies of the pod for French air force and navy Rafales, along with seven MINDS image exploitation systems. It is scheduled to complete final qualification on the Rafale F3 next month after more than 100 flights, with subsequent operational experimentation at the Mont De Marsan military flight test center leading to operational deployment early in 2010. Larroque said he expects future upgrades to include multi-spectral or hyper-spectral sensors.

The existing Damocles targeting pod, meanwhile, is evolving to meet new operational requirements. The aim with the new Damocles XF extended-features variant, said project manager Pascal Jourdan, is to produce “the world’s best performing targeting pod.”
The usual phases of engagement start with long-range target recognition and accurate designation at stand-off ranges. Damocles already does that, Jourdan said, but at the short ranges and in the complex environments typical of urban conflict the requirement is for positive identification of targets by day or night.

Damocles XF, accordingly, uses real-time image processing to produce a much clearer infrared picture and adds a new daylight CCD camera with continuous zoom, along with symbology and automated functions to reduce crew workload.

Without increasing the existing pod’s dimensions or approximately 600-pound mass, the XF variant also adds a high quality video data link so that imagery can be transmitted to tactical air and forward air controllers for confirmation of target identification and post-engagement battle damage assessment.

In addition to the information from radar, optronic and EW systems, there is an IFF interrogator to determine whether an object on the ground or in the sky is friendly or hostile. The missiles’ IR seekers provide further information, as do the pilot’s own eyes, and more input comes via data link from other fighters, airborne command and control aircraft and ground control centers.

To synthesize all this data so the pilot has a single track for each target on the ground or in the sky, the Rafale relies on the Thales modular data processing unit. The MDPU has up to 18 modules, each with 50 times more processing power than the computer used by early Mirage 2000-5s.

The data fusion process starts by establishing consolidated tracklines and refining primary information from the sensors. Sharing the track information helps overcome individual sensors’ limitations in terms of wavelength, frequency, field of regard and angular or distance resolution. The final stage involves assessing the level of confidence in the consolidated tracks, suppressing redundant track symbols and decluttering the displays. The result of the data fusion process can also be broadcast to other members of allied forces to enhance their situational awareness.

Given all this enhanced capability, Thales is optimistic about the Rafale’s export prospects, with potential buyers also including the UAE, Kuwait, Qatar, Greece and Libya. “It’s true that we haven’t sold the Rafale,” said Gerard Christmann, Thales Aerospace general manager business line. “But you have to consider that it’s a completely new aircraft. We delivered the first one to the air force only in 2006.

“The Rafale is a very new aircraft; it’s totally normal to start selling it now that it’s completely mature. We are starting a big export promotion with Dassault and [engine-maker] Snecma,” he said, pointing out that it took 15 years for the Mirage 2000 model to win its first major export order after initial delivery to the French air force.

The airplane’s open architecture will permit a lot of improvement in the future, Christmann added, so the Rafale of 2009 is not the end of the story. “There will be a succession of in-production Rafales over the next 20 or 30 years, and we expect to win some, if not all, of the competitions we enter,” he said.