Denel's SAMs a hit

By Leon Engelbrecht, ITWeb senior writer

Johannesburg, 16 Apr 2008

Denel's hi-tech SA-designed and developed Umkhonto surface-to-air missile (SAM) has been selected by the Swedish Navy for fitment aboard its new Visby-class stealth corvettes.

This will make it the third user of the missile and associated IT, after the SA Navy and that of Finland, says Denel Dynamics CEO Jan Wessels.

Research firm Forecast International put the value of the deal at $150 million, about R1.2 billion at the current exchange rate, for five systems.

Wessels add that the SA Army has also contracted Denel to design and develop a land-based six-shot launcher and infrastructure for the missile as part of its Ground Based Air Defence System (GBADS) phase two, also known as Project Protector. This should earn the state arms company several million rand more.

Defence department officials last year told Parliament that phase one of GBADS, which involves an imported missile and radar system that has been plagued by software integration issues, has so far cost R801 million.

Fire power

Denel Dynamics air defence missiles executive manager Machiel Oberholzer says the Umkhonto is optimised to shoot down anti-ship missiles and is armed with its 23kg warhead that destroys anything within 10m of its detonation point. "The Umkhonto has one of the largest warheads in its class," he says.

While its fuse is supplied by a European company, the bulk of its electronics, electro-optics and IT are custom-made at Denel Dynamics' Centurion plant. "The heart of the system is the front-end, the seeker head," Oberholzer says. "We have quite an investment in cryogenics, because the seeker has to be cooled to -85 Kelvin (about -200 degrees Celsius) to function.

"The seeker uses specialised optics to focus energy on a detector that is made in-house," Oberholzer adds. "Not many countries have this capability.

"Some of our best capability lies in the signal processing. At the very best you have a faint signal," he says, explaining that the signal processor only has a few instants to decide what the data means. "Is it a target? Is it friend or foe? Where is it heading?"

Oberholzer says the signal processor also discerns between its selected target and countermeasures, such as flares, used to distract it. "We can discriminate the target from even the latest flares. So you can set the signal processing to ignore the flare and stay true to the target," he says.

Local feat

Wessels says this is why SA needs to be able to build its own missiles. "Why do we need a missile capability, why don't we just buy these things? One of the benefits - with signal processing - is that you can tweak your product to discriminate between the target and countermeasures. An imported product has a generic setting which you will not be able to customise to your precise requirement" - which is to save a ship and the lives of its crew under air or missile attack.

Oberholzer says Denel has now completed the delivery of Umkhonto to the SA Navy, which has a system aboard each of its four Valour-class frigates.

Six systems have been delivered to Finland and have been fitted to four Hamina class missile boats and two H"ameenmaa class minelayers. "We are busy with the production of their missiles."

Returning to the Swedish project, Oberholzer notes: "We are busy with the study phase. It is quite an achievement for a small country like SA to be playing this field. We've got customers knocking at the door and we have a niche product here with little competition."