Original URL: http://www.theregister.co.uk/2009/08/26/jlens_first_flight/

Blimp radar makes first flight

Defence against terrorist death drones, kamikazes

By Lewis Page

Posted in Science, 26th August 2009 10:04 GMT

Vid A new US military radar system, suspended beneath a tethered "aerostat" balloon so as to see beyond the horizon, made its first flight yesterday. The JLENS blimp-scanner is intended to finger such things as enemy cruise missiles or unmanned aircraft.

The US military - particularly the Army, as opposed to the Air Force - has been worried for some time about its ability to detect and strike at low-flying threats. Where a cruise missile, "loitering munition" or unmanned aircraft is flying low, a ground-based radar will only be able to detect it if it passes within a few miles above the radar's horizon. Thus conventional air-defence missile batteries need to be put close together to create a defensive line against such threats.

The conventional solution would be to put a radar into a high-flying AWACS aircraft, but AWACS planes are horrifically expensive and are required in numbers if constant patrols are to be kept up.

JLENS is intended to be a lower-cost solution, putting its sensors in tethered aerostats moored to mobile ground stations. Working with JLENS, a ground missile which has the power to hit high-flying, faraway targets can now use that power to reach over the horizon to a low-flying target initially invisible to its own sensors.

"JLENS makes our current weapons systems more effective," according to project chief Lieutenant Colonel Steve Wilhelm. "Missiles that were once limited by their organic radars can now meet their full kinematic potential because of the extended ranges provided by JLENS radars. This first flight brings us one step closer to providing that capability."

A fully operational JLENS system will deploy two aerostats, one with a search radar sweeping wide areas and the other with a multifunction fire-control and tracking radar cued by the search blimp. The aerostats are manufactured by TCOM, and US weapons globocorp Raytheon does the sensors and networks.

The balloons are intended to have a ceiling of almost 15,000 feet and be able to stay up and operational for as long as 30 days. Raytheon says the kit should be in service with the US Army from 2012.

Systems of this sort are seen as a possible solution to terrorist or insurgent threats such as suicide-piloted or automated light aircraft, or small/improvised drones converted into poor-man's cruise missiles. The Indian armed forces decided to deploy coastal aerostat early-warning radars in 2007, worried about possible attacks from the Tamil Tigers' improvised jungle air militia. ®