Story ID: 
Elisra melds offense and defense
By: Charles Alcock
Caption: The maxim that attack is the best form of defense implies that the two modes are effectively two sides of the same combat coin.
Word Count: 647
The maxim that attack is the best form of defense implies that the two modes are effectively two sides of the same combat coin. Elisra’s designers see it this way, claiming that their latest combined defensive aids suite (DAS) and intelligence, surveillance, reconnaissance, target acquisition and search (ISTAR) systems represent the most complete all-in-one-box package available for modern warplanes. This covers functions such as electronic support measures (ESM), as well as protection against laser and infrared threats.

“Fighters have to be equipped with both self-protection and attack platforms. These are parallel systems so why should they not share the same sensors and processor,” said Nati Catran, the group’s deputy marketing vice president. “Why have double systems when all the key data can be handled in one spectrum.”

What Elisra has on display in the vast Israeli Pavilion here at Le Bourget is claimed to be the first example of entire DAS and ISTAR functions being combined in one line-replaceable unit. By reducing the number of boxes required in a fighter, this approach makes for much easier installation, while also cutting life cycle costs and spares requirements. But no less importantly, explained Catran, it also significantly reduces pilot workload.

Elisra’s single box includes the following elements: DAS controller, which does the data fusion and decision making; radar warning receiver; laser warning controller and analyzer; radio frequency jammer; and a chaff and flare dispenser.

“The RWR (radar warning receiver) antenna must be able to measure accurately and at the same time the interpulse data of the radar has to be measured,” Catran told Aviation International News, explaining the type of combined processes through which the DAS essentially serves as the ISTAR system.

“Everyone has been thinking about doing a system this way, but Elisra is the first to do it,” he added. Technological advances such as digital receivers and more advanced computer processors have made the all-in-one-box concept feasible, greatly reducing weight and power-supply requirements.

Under another aspect of the same concept, Elisra can offer the following functions, all using infrared sensors: a passive approach warning system, panoramic displays (using IR cameras), collision avoidance and conflict resolution and weapons direction capability. “The user is getting all these functions for the price of one system–a DAS and a ESM for the price of a DAS,” concluded Catran. In other words, providing situational awareness is another task on top of other DAS and ISTAR functions.

Maybe this sounds too good to be true–surely there are reliability issues? “Not really,” said Catran. “This is no different from the various sensors of the human body (eyes, ears, nose, etc) working together. However, there is a risk that the central processing unit will be damaged and so we have redundancy for this.”

The Israeli air force is already using the DAS/ISTAR combination on various aircraft, including helicopters. Catran said that the same system can be applied for different force requirements so that, for example, AgustaWestland’s Merlin helicopters could be equipped for emerging urban attack roles. “Future helicopter programs require a high degree of commonality and this is possible through DAS/ ISTAR,” he stated.

Elisra is also looking to apply the all-in-one concept to new military aircraft programs such as the AgustaWestland Future Lynx multi-role helicopter. It also sees potential for retrofit programs as operators such as the U.S. forces in Iraq see a need for defensive aids to protect against ground-launched weapons.

The company is thinking of applying the all-in-one DAS/ ISTAR concept to unmanned air vehicles. This would use multispectral sensors and data dissemination systems to relay information to network centric warfare platforms.