韩国部署500公里预警机，加入美军全球预警网络的前沿节 ...

Military to Deploy Early Warning Aircraft
The E-737 The E-737

The military will deploy E-737 airborne early warning and control aircraft in July that have a 400 km surveillance range. The aircraft are capable of simultaneously monitoring 1,000 aircraft, track 300 targets and search the skies for low-flying North Korean AN-2 infiltration airplanes.

Boeing unveiled the new planes, dubbed "Peace Eye," and said the first plane will be delivered to South Korea in June, a month earlier than planned.

Seoul will spend W2 trillion (US$1=W1,128) until the end of 2012 to procure four E-737s. The first one will be built in the U.S. and the rest will be fitted with radars and undergo final modification in South Korea.

South Korea will be the third country in the world to operate the E-737 after Australia and Turkey. The E-737 is fitted with Northrop Grumman's Multi-mode Electronically Scanned Array (MESA) radar and an identification friend or foe (IFF) system. It performed flawlessly in several test flights under rainy, snowy and windy conditions. Boeing said that the planes fly at an altitude of between 9 km to 12 km and can detect all low-flying aircraft that infiltrate using mountainous terrain.

Unlike the disc-shaped radar of existing airborne warning and control systems, which rotate once every 12 seconds to transmit and receive radar signals, the MESA radar can freely transmit and receive radar signals in any direction and distance. Under normal conditions, the maximum surveillance range is around 370 km, but focused transmissions of radar signals in one direction could expand the maximum range up to 500 km, making the E-737 capable of monitoring all of North Korea when flying close to the Demilitarized Zone.

The E-737's radar is also capable of monitoring enemy vessels and other maritime targets. Surveillance data can be transmitted to command headquarters and other weapons systems, including F-15K fighter jets. The E-737 is also capable of firing aluminum chaff and flares to evade heat-seeking missile attacks and is fitted with six missile advance warning systems on top of and under the fuselage.

The military will operate the aircraft in three shifts lasting eight hours each. The Peace Eye can fly up to 20 hours after each aerial fueling.

Radar

The MESA multi-role electronically scanned array radar is being supplied by Northrop Grumman Electronic Sensors and Systems Division, based in Baltimore. Tenix Defence Systems of Adelaide, Australia, is supplying some components and modules for the radar. MESA provides 360° coverage and a range of over 200nm.

The radar has a system track capability of 3,000 targets and can track air and sea targets simultaneously.

The system's variable track update rates and dedicated tracking modes allow the operator to track allied and hostile high performance aircraft while continuously scanning the area of operations.

The electronically scanned array features an assembly of transmit and receive modules, operating at L-band and sharing three apertures to provide the 360° coverage. The radar system provides a high level of operational capability because the system is dynamically structured to match the changing mission requirements. When an operator requires a long range view of a selected sector of the operational area, then the relevant system modes can be selected to initiate the search of that sector at more than twice the nominal uniform surveillance range.

An integrated identification friend or foe system (IFF) is combined with the primary radar and uses the same aperture as the primary radar, which avoids target correlation problems. The IFF system has an operational range of over 300nm.

The distinctive 'Top Hat' radome provides a low aerodynamic drag profile while meeting the requirement for fore and aft coverage. Two large strakes are fitted on the underside at the rear section of the fuselage. The strakes provide an aerodynamic balance to offset the effect of the MESA radome on the upper surface of the fuselage. In January 2005, flight tests of the aircraft were temporarily suspended while the upper surface of the radome was raised by about 100mm, to improve radar performance.