|Gregor Ferguson From: The Australian October 23, 2010 12:00AM
A LITTLE bit of history was made this month in Western Australia when an Anzac-class frigate, HMAS Perth, slipped her moorings and sailed into burn Sound for the first time with an all-new Australian radar system fitted.
The ship has been moored at the Australian Marine Complex in Henderson, just south of Fremantle, being fitted with solid-state radars designed and manufactured by Canberra-based firm CEA Technologies. These are mounted atop a sleek, futuristic-looking new lightweight mast built by BAE Systems Australia.
The Ceafar and Ceamount radars will transform the ship's ability to protect itself against enemy aircraft and missiles. The six-face Ceafar radar will detect and track incoming aircraft and anti-ship missiles; the four-face Ceamount radar is an "illuminator" -- its radar energy will bounce off the incoming target to guide the ship's Evolved Sea Sparrow Missile (ESSM) all the way to impact.
As well as being extremely accurate, this combination allows the ship to deal with multiple incoming missiles at once -- sufficient, says Defence, to stay ahead of any foreseeable threats until the Anzac frigates retire in about 2033.
Defence sources told The Australian HMAS Perth will be tied up at the naval base at HMAS Stirling while the new radars and heavily upgraded Saab Australia combat system undergo Harbour Acceptance Trials. The new radars will be set to work for the first time next month, according to a source in the project, but the ship won't start its formal sea trials until late February.
The Ceafar and Ceamount radars have been under development for a decade. Ceafar consists of 30cm by 30cm "tiles" each made up of 64 miniature, solid-state transmitters and receivers -- a so-called electronically scanned Phased Array Radar with no moving parts. Each of its six antenna faces is made up of a 4x4 array of these tiles. The smaller Ceamount consists of 20cm x 20cm tiles with 256 elements, and its four antenna faces consist of 2 x 2 arrays of tiles.
Both radars are similar to the Aegis system on the RAN's new Air Warfare Destroyers, and siblings (in a technology sense) of the electronically scanned antenna on the RAAF's Wedgetail early warning aircraft.
But the Australian radars represent the fourth generation of this sensor technology: they are lighter and smaller so can be mounted high on the masthead of a ship instead of on the superstructure. Nevertheless, shipbuilder BAE Systems Australia has had to design new lightweight masts to reduce "top weight" on the frigate while carrying the necessary cables, cooling elements and other equipment.
The development program has involved, first, the testing of single tiles on land then on a test rig at sea. In 2008 a full-scale prototype was installed on HMAS Perth to demonstrate that the radar's beam could be switched from one radar face to the next without losing the target. Meanwhile Saab Systems has been upgrading its proven 9LV Mk3 combat system to cope with the increase in radar, weapons and communications data which the upgraded Anzac frigates will generate.
The sea trials next year will test the Ceafar radar's ability to detect and track a mass of incoming targets. The Ceamount "illuminator" faces an even tougher challenge: its PAR technology means its beam can skip rapidly between multiple targets to provide continuous guidance for ESSMs being launched in different directions.
This ability to achieve multiple so-called "channels of fire" from a single illuminating radar is a unique feature of Ceamount. Traditional illuminators with their dish-type antennas can't do this because they can point in only a single direction at a time. As a result ships with only a single illuminator can engage only one target at a time, which means a mass attack can easily saturate their defence.
It's this vulnerability that has driven the RAN's Anzac frigate Anti-Ship Missile Defence (ASMD) project, Sea 1448. The Ceafar and Ceamount element in Phase 2B (which includes a minor navigation radar upgrade) is worth $459 million.
In next year's sea trials, ships, aircraft and carefully simulated missiles will put Ceafar and Ceamount to the test. If all goes well the RAN and CEA Technologies will know by April if they're working properly. If they are, the federal government is expected to give the green light for a similar upgrade to the remaining seven Anzac-class frigates as early as the third quarter of next year.