Typhoon Partners Focus On Sensor UpgradeJul 19, 2010
By Douglas Barrie, Robert Wall
Munich, Berlin
Ensuring that an AESA radar remains on track in its domestic constituency is a key element of sustaining Eurofighter Typhoon campaigns in crucial export markets, including India and Japan.
A full-scale program to develop an active, electronically scanned array (AESA) for the Typhoon is about to be launched by the partners—Britain, Germany, Italy and Spain.
The Eurofighter consortium has been in discussions for some time with the four governments regarding a potential contract for an AESA to succeed the Captor mechanically scanned radar on the Tranche 1 and 2 aircraft.
The consortium has made it clear it would begin work even without a formal agreement to ensure the 2015 fielding date needed to meet the planned in-service date for the Tranche 3B Typhoons. “The goal is to protect our export market,”says one Eurofighter executive.Industry completed a risk-reduction study in April aimed at defining the exact technical parameters of the AESA and ironing out industrial and technology differences between key stakeholders.
One issue is the U.K.'s and Germany's interest in supporting their transmit/receive (T/R) module industrial base. With that in mind, the consortium devised an open architecture design that should allow a radar front end using T/R modules from either EADS of Selex with minimal other changes, says another European industry official.
But designers also are trying
to leave room in the architecture for enough flexibility to guarantee that the radar can be exported and does not fall into restrictions from any of the core member countries.In parallel, the U.K. is pursuing a national technology demonstrator AESA project. Previous related research included the Selex Galileo
Advanced Radar Targeting System (ARTS), which was test flown in the U.K. and U.S. using a Tornado GR4A. ARTS was supposed have led to a radar upgrade for the GR4A, but the project was shelved because of funding problems.
The successor, believed to be known as
Bright Adder, is intended to fit the main elements of an AESA on a two-seat Typhoon. The program is nearing the Defense Ministry's Initial Gate phase of the funding-approval process. The go-ahead had been set for earlier in the year, but national elections delayed this.
The intent would be to move to the Main Gate
decision point in the second half of 2011, clearing the way for the acquisition of a production AESA. The U.K.'s aim appears to be to maintain as much commonality as possible with the four-partner-nation effort, although the technology demonstrator will be a national program.The U.K. is particularly interested in pursuing the electronic attack (EA) capacity of AESA technology; at least some of the ARTS trials were intended to explore this. The Royal Air Force's Alarm 2 missile is due to be withdrawn from service around 2013-14, and an EA capability would partly compensate for the shortfall.
The AESA concept being considered for the related projects uses a swash-plate design of the repositioner that moves the radar antenna to increase the field of regard to more than 90 deg. Fixed AESA arrays suffer from performance degradation at look angles of greater than ±60 deg. Options for addressing this deficiency include using adjunct arrays or moving the main array, though far more slowly than the snap rate of a traditional mechanically scanned array.
Developers have had to revise the initial swashplate design as a result of a polarization issue with the identification-friend-or-foe system and the desire to keep its orientation constant. The repositioner first had only a single rotating joint, but has now shifted to a two-part joint structure.
The Eurofighter consortium is trying to preserve, where possible, the use of the current Captor-M radar elements, including the receiver and processor. In fact, the AESA should reduce the number of line replaceable assemblies.
The U.K. has requested that all Tranche 3A Typhoons be provisioned for the AESA, although the radar would be introduced as part of a retrofit. This means the aircraft is able to handle the power and cooling requirements, although the higher-power generators are not being built in at this point.
Eurofighter officials are bullish on the projected performance of the AESA, noting it will be more capable than many rivals. Typhoon's radar will have twice as many T/R modules compared with the smaller Rafale radar, and will also be larger than the F-35's while having more modern technology than the F-16's and F-15's radar, they assert. Flight trials of a preproduction version are slated for 2012.The weight of the new antenna could shift the Typhoon's center of gravity slightly forward, which will be offset with ballast in the aft fuselage. However, another industry official notes that adding thrust-vector control to the Eurojet EJ200 powerplant would be a more efficient way to tackle the issue.
In parallel with the AESA introduction, the Typhoon partners will also start to receive MBDA Meteor rocket-ramjet-powered beyond-visual-range air-to-air missiles.
The Meteor capability is viewed as a potential discriminator in some of the ongoing export campaigns, particularly in Japan. Air superiority is believed to be the primary requirement for the fighter procurement, which is now expected to begin in the first or second quarter of 2011.
The radar is also a critical element in the Indian campaign. Eurofighter would build the first 18 Typhoons in Manching, Germany, before shifting assembly to India.
This year, the Typhoon will start to receive upgrades as part of the so-called Phase 1 enhancement program. This introduces a range of improvements, the final elements of which will be rolled out in 2012. Included are the full integration of the Raytheon Paveway IV laser-guided bomb with GPS backup, Link 16 data link, IRIS-T air-to-air missile and electronic warfare enhancements. Full integration of the laser designator pod also is being implemented. Flight trials to validate the package are underway on four aircraft.
Previously, the Eurofighter consortium wanted to add another round of upgrades through the block approach (nota: se habría llamado P2E (Phase 2 Enhancements)),
but determined that it would be too difficult to gain approval for major packages. Instead, the consortium is now looking to phase in improvements every 2-3 years. This strategy also reduced the sticker shock for the four core countries.The rolling-upgrade path will also likely be seen in how the AESA and weapons are introduced.
The initial focus for the radar will be on air-to-air capabilities to support Meteor. About two years later, air-to-ground modes will follow to add Brimstone, Taurus and Storm Shadow ground-attack capabilities, notes a Eurofighter executive. An inverse synthetic aperture radar mode to fire anti-ship missiles would come in another step.Eurofighter is also refining concepts of operation for the Meteor. Initially, the approach was to consider the weapon simply as an extended-range AIM-120 Amraam.
The specified kinematic performance of the Meteor, however, is intended to provide the ability to engage maneuvering targets—with a high probability of kill—at ranges well beyond that of the Amraam.Meanwhile, industry is dealing with several other issues,
including problems with the infrared search-and-track system, but these have apparently been resolved.Also still ahead is integrating secure communications for non-NATO members. This is proving to be a challenge in Saudi Arabia's case, although industry officials point out that it is not a Saudi-specific problem but one that affects non-NATO members more broadly because of security restrictions.
In the meantime, fighter production now tops 220 units; the U.K. is the largest operator, followed by Germany. More than 73 Tranche 2 aircraft have been delivered.
http://www.aviationweek.com/aw/generic/ ... or+Upgrade 
Sobre la polivalencia del EFA. La primera cita dice bien claro que uno de los requisitos de diseño básico era ser polivalente, sindo la tarea AA la principal. Y la segunda cita lo confirma extendiéndose más. El comienzo se refiere a cómo es posible que haga ambas tareas y luego sobre porqué su capacidad AS inicial es reducida: no por imposibilidad o por no haber sido proyectado como polivalente, como dicen algunos, si no por exigencias de las naciones:
