美 Raytheon 社가 개발 중인 NCADE 와 AESA 레이더...

 

美 Raytheon 社는 공대공 미사일을 이용한 탄도탄/위성요격시스템, NCADE (Network Centric Airborne Defense Element) 를

약 4년여전 부터 개발하고 있습니다. 마침 AW&ST 최근 호에서 NCADE 와 AESA (Active Electronically Scanned Array) 레이더

관련 기사가 있어 소개합니다.

 

NCADE 의 개발 상황과 함께 AESA 레이더에 대한 내용도 있습니다. NCADE 의 개발이 성공적으로 완료되기 위해서 AESA 의

역할이 더욱 중요하다는 의미로 이해가 되는 기사로 생각합니다. 한편으론 미국이 AESA 레이더 수출에 대해서 엄격하게 통제

하는 이유를 알게되는 기사라 할 수도 있습니다.

 

이러한 점에서, 우리 대한민국 공군도 3차 F-X 도입사업과 KFX 개발사업에서는 AESA 레이더가 선택이 아닌 필수 장비로 포함

되기를 바라며, 나아가서 KF-16 성능개량 사업에서도 AESA 레이더의 장착이 이루어졌으면 하는 바람입니다.

 

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Boost-Phase Battles

The first minutes of flight will no longer be a safe zone for ballistic missiles

Aviation Week &Space Technology, 06/28/2010

Author: David A. Fulghum

 

A huge gap in U.S. ballistic missile defenses may soon be filled by air-to-air weapons fired from fighters or unmanned aircraft fitted with long-range sensors.

 

The problem area is boost phase — from launch to low space, about 400 km. (250 mi.) altitude. Study of boost-phase intercept (BPI) in the 1990s was abandoned because of the short range of fighter radars and missiles and the immaturity of unmanned aircraft. But the idea of attacking during boost phase — when ballistic missiles are slow, hot targets — remains attractive to military planners.

 

“Right now, there is a gap because no weapons can engage there,” says Philip Pagliara, Raytheon Missile Systems’ program manager for the Network-Centric Airborne Defense Element (NCADE).

 

“We want to catch missiles where they are the most vulnerable. Studies found that the air-launched, hit-to-kill mission is operationally feasible and technically viable. So we think fighter aircraft and other highly mobile airborne assets give you flexibility to counter ballistic missile threats worldwide.”

 

The push for such a capability came from the warfighter community, and there are already discussions of making the project an urgent-procurement, quantity buy.

 

Moreover, the fighter-radar-missile combination “would make a lot of sense for Asian countries” that fly the same aircraft as the U.S.,” says Arnie Victor, director of F-15 business development at Raytheon Space and Airborne Systems. “There are a lot of concerns in the region since [North Korean] ballistic missiles were shot across Japan.”

 

Because of the location of ballistic missile launch sites, many of them would be with a range of missiles fired from aircraft in international waters.

 

The U.S. Air Force and the Missile Defense Agency believe they are creating an air-launched, gap-filling solution. They, along with Raytheon, are considering testing the newest fighter-carried, active, electronically scanned array (AESA) radar in conjunction with an extended-range version of the AIM-120 advanced medium-range air-to-air missile (Amraam).

 

“We’re basing this on the Amraam form factor and existing production components,” Pagliara says. “We’re adding some new components and integrating them into a missile that looks like an Amraam but that can do a new mission — ballistic missile defense. The real key is that it uses logistics support that is already in place. If you can shoot an Amraam, you can shoot an NCADE. It meets all the requirements for internal carriage for those types of platforms [such as the stealthy F-22]. We have not shot NCADE from a UAV yet, but it is on our horizon.”

 

Raytheon, Defense Advanced Research Projects Agency and Air Force officials will not discuss radar ranges. But those with insight into the technology say radar ranges vary from 90 mi. with an F-16-size AESA radar to 150 mi. with an F-15 size antenna. That kind of performance, mixed with new algorithms and advanced data links, could subsequently make the combination of the faster, higher-flying F-22 and NCADE a viable weapon against short-range ballistic missiles (SRBMs) in the terminal phase and possibly low-flying satellites, says a senior U.S. Air Force official.

 

“There have been some analyses and tests of the hardware that show engaging terminal threats is feasible,” Pagliara says. “We’re looking at both [ends] of these threat flight profiles. We’re also looking at the altitude gap where other weapons don’t engage. If you have to operate entirely in the atmosphere during the first part of the [theater ballistic missile] flight, the standoff range and the time available to engage the threat are shorter. But if you can fly into the high endo- and exoatmosphere, you increase the standoff range and engage later in the flight.”

 

NCADE is a two-stage missile with an extended-range Amraam solid-fuel rocket motor as the first stage, a separation joint, and a second stage with a divert attitude control system and guidance-unit electronics and an AIM-9X seeker.

 

The second stage “gives us the altitude capability to increase the battlespace significantly,” Pagliara says. “It allows you to operate in the high endoatmosphere’s thinner air and exoatmosphere, where there is no aerodynamic control. It also has an axial thruster so that you can maintain forward velocity.”

 

For the upcoming test, the NCADE missile will carry an electro-optical/infrared (EO/IR) sensor from the shorter-range AIM-9X. The new design is sized to be carried internally or externally by any aircraft that can carry the Amraam.

 

Raytheon demonstrated the concept in December 2007. The test was conducted using two Arizona Air National Guard F-16s, each carrying an NCADE prototype, that shot down a 14-in-dia. Orion sounding rocket at White Sands Missile Range, N.M.

 

“We had a skin-on-skin contact with the target missile,” Pagliara says. “The trailing missile [IR sensor] recorded the leading missile knocking a fin off the target missile and poking a hole in the motor. It was the first time that we know of that an air-launched missile hit a ballistic missile.”

 

U.S. Air Force research shows that short- and medium-range missiles are rapidly proliferating. For example, coalition forces intercepted and then released a ship-load of mobile Scud missiles and fuel being delivered to Yemen from North Korea in 2002. This year, Israeli officials reported Scuds were being delivered to the Hezbollah organization in Lebanon.

 

In nations other than China, Russia and those in NATO, there are about 5,500 SRBMs with ranges of less than 1,000 km. (620 mi.) and 350 medium-range ballistic missiles. That is considered a far greater concern than any threat from ICBMs.

 

Long-range, small-target, AESA radars made by Raytheon and Northrop Grumman are already, or soon will be, operational in various forms on the Boeing F-15C/E, F/A-18E/F and EA-18G, as well as the Lockheed Martin F-22 and F-35. These front-line fighters could operate in combat air-patrol orbits within range of the ballistic missile launchers. But a longer-term solution would be to put the radars and missiles on larger unmanned aircraft such as the turboprop-powered Predator B or the higher-flying, turbofan-powered Predator C.

 

The operational concept for both manned and unmanned is similar.

 

“A fighter can engage along with its own onboard AESA and infrared search and track [IRST],” Pagliara says. “At the missile’s launch, the aircraft can detect, track and launch the NCADE. The AESA really comes into play in acquiring the target and building a track file. Its enhanced capabilities allow it to detect small targets at long range. The interceptor acquires the ballistic missile with its own IR seeker and makes the final intercept.”

 

New communication conduits, such as the Common Data Link or Radar Communications Data Link, also allow cueing from offboard sensors.

 

“If you can get an external cue either on board or off board to look in a smaller volume [of the battlespace], this greatly increases the range of the AESA because it doesn’t have to look everywhere,” says Ramon Estrada, director of F-15 growth programs at Raytheon Space and Airborne Systems.

 

“If there is cloud cover or bad weather, you can still have a radar solution without infrared,” Victor says. “A cue could also be from a different tactical or [intelligence, surveillance and reconnaissance] platform such as Joint Stars or ground information passed via data link.”

 

AESA radar offers the option of communicating large radar-map files — perhaps to find missile launchers — to other aircraft or ground stations. It also can combine EO and IR data with other functions. Other communication links in the package pass detection and target-location information during the missile’s flyout.

 

“Once the aircraft has developed a predicted intercept point and initialized NCADE, it will launch the missile, which flies out on its first-stage motor,” Pagliara says.

 

“We will have the IR dome and nose cone covered. At a certain altitude, when we start losing aero-control, we separate the first stage and continue flight to the predicted intercept point,” he says. “We uncap the nose cone and acquire the target with the IR seeker on the second stage, and continue through the terminal engagement.”

 

But if manned fighters or remotely piloted aircraft are out on ballistic missile air patrol, they should also be able to conduct missions such as ground attack, say Air Force planners.

 

“If you can see [a target], you want to be able to shoot it,” Pagliara says. “We want the aircraft carrying NCADE to remain multi-mission platforms. With a mixed load-out [of air-to-air and air-to-ground weapons] you can protect a strike package or you could launch against the ballistic missile in flight and then go in and kill the TEL [transporter, erector and launcher].”

 

Victor says, “The AESA offers an air-to-ground capability. It includes a high-resolution SAR [synthetic aperture radar mode] that allows you to find, identify, track with GMTI [ground moving-target indicator] and strike a target that begins to move after a launch. That way you can kill the missile and the guy that shot it.”

 

The capabilities of AESA — which include generating radar maps and moving-target overlays — allow simultaneous operations to be conducted that yield a complete 3D picture of a battle.

 

Raytheon contends there is still considerable growth in the fighter, AESA-radar and NCADE missile combination.

 

“The way you expand the envelope is to make a bigger motor,” Victor says. “Right now it’s not part of the program, but that’s what will produce more kinematics [maneuvering], longer range and faster speeds.”

 

Already Raytheon researchers have modified the AIM-9X production seeker for the NCADE mission by developing algorithms that allow the seeker pick the missile body out of the plume that surrounds it.

 

 

  ⓒ Raytheon