Original URL: http://www.theregister.co.uk/2007/05/18/balloon_radar_v_tiger_terrorist_airforce/

India to deploy tethered blimp radars

Worried about Tamil Tiger air force

By Lewis Page

Posted in Bootnotes, 18th May 2007 13:20 GMT

The Indian armed forces are using radar-carrying static balloons to provide an early warning of terrorist air strikes, according to reports.

Much interest has been aroused in defence circles during recent months by the air raids mounted in Sri Lanka by the Liberation Tigers of Tamil Eelam (LTTE, or "Tamil Tigers"). The conflict between the Sri Lankan government and the separatist Tigers has normally been seen as a counter-insurgency conflict like many others ongoing around the world, in which relatively well-armed conventional forces battle guerillas who favour tactics such as suicide bombing, ambushes, and assassination.

Many governments, including the US, list the Tigers as a terrorist organisation.

In recent months, however, the Tigers have mounted several bombing raids against targets in Sri Lanka, reportedly using modified light aircraft of Czech manufacture. The Tiger pilots have flown in and out at low altitude, which makes them difficult to detect using ground radars.

India nowadays prefers not to get too involved in the Sri Lankan fighting off its southeastern coast, after suffering a bloody nose during a military intervention and the assassination of former Prime Minister Rajiv Gandhi by the Tigers in 1991.

But the Indians are worried that the fighting could come to them, in particular in the form of Tiger air attacks. Lacking a big fleet of AWACS planes or similar conventional-type airborne radar platforms, Indian military planners are thinking outside the box.

India Defence reports that the Indian Air Force will deploy aerostat radars on the southeastern Tamil Nadu coast. The aerostats are tethered blimp-like balloons carrying phased-array radars which can detect approaching aircraft from afar, even if they fly at low level. The IAF purchased two of the EL/M-2083 systems from Israel in 2004, and apparently has been sufficiently pleased with the balloon-borne eyes-in-the-sky that a further four have been ordered.

The aerostats aren't as vulnerable as they might seem; they aren't highly pressurised. This means that they won't burst, and leak only slowly if penetrated. An aerostat will stay up for hours even with its envelope pierced by hostile fire. Filled with helium rather than hydrogen, there's no risk of a Hindenburg style explosion.

Reportedly, small Russian-made ground radars have also been deployed, in particular at the Kalpakkam nuclear plant. ®