View source for Euroradar CAPTOR

{{Short description|Captor by Euroradar as seen on the Eurofighter Typhoon (CAPTOR-M/E, Mechanical/AESA)}}
{{Multiple issues|
{{Expand German|EuroRADAR CAPTOR|date=December 2017}}
{{Update|date=April 2021|reason=Recent developments not included, i.e. European Common Radar System (ECRS) variants}}
}}

{{Infobox radar 
|name        = Euroradar Captor
|image       = ILA Berlin 2012 PD 193-Detail-2.jpg
|caption     = Captor-E Demonstrator
|country     = [[Germany]], [[Italy]], [[Spain]], [[United Kingdom]]
|introdate   = 
|number      = 
|type        = '''Captor-M''': Solid-state, mechanically scanned array radar<br />'''Captor-E''': [[Active electronically scanned array|Active electronically scanned array (AESA)]] radar
|frequency   = [[X-band]]
|range       = 
|altitude    =
|diameter    = 
|azimuth     = 
|elevation   = 
|precision   = 
|power       = 
}}
[[File:CAPTOR E.jpg|thumb|Captor-E radar pictured in London in 2019]]
The '''Euroradar Captor''' is a next-generation mechanical multi-mode pulse [[Doppler effect|Doppler]] [[radar]] designed for the [[Eurofighter Typhoon]]. Development of Captor led to the Airborne Multirole Solid State Active Array Radar ('''AMSAR''') project which eventually produced the '''CAESAR''' (Captor Active Electronically Scanned Array Radar), now known as '''Captor-E'''.

==Development==
{{Proofreader needed|EuroRADAR CAPTOR|de|date=February 2024}}

=== Early development ===
In June 1985, discussions began amongst various concerns to sound out the possibility of cooperation for the EFA, the project that would later become the Eurofighter, radar. The United Kingdom chose [[Ferranti]] as the leading contract partner, Germany [[AEG (German company)|AEG-Telefunken]] and Italy [[FIAR]]. Spain, which had no radar experience, played only a minor role,<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1985/1985%20-%201955.html|title=flightglobal: ''Radars look down on Paris'', 16 June 1985}}</ref> later selecting Eesa as the main contractor. Towards the end of June 1985, a memorandum of understanding was signed between the UK, Germany, France, Italy and Spain to develop a joint radar for the EFA. France had already indicated at the time that it intended to withdraw from the programme. The French company Thomson-CSF was thus faced with a dilemma, as it would have liked to participate in an EFA radar.<ref>[http://www.flightglobal.com/FlightPDFArchive/1985/1985%20-%202109.PDF flightglobal: ''Five study EFA radar'', 29 June 1985] (PDF; 131&nbsp;kB)</ref> Therefore, in 1987, [[Thomson-CSF]] negotiated with Ferranti to secure a share of the work. Specifically, the travelling wave tube was to be supplied which was possibly the same one that was to be used in the Rafale. In March 1987, Ferranti and AEG sent their offers to [[Eurofighter GmbH]].<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1987/1987%20-%200004.html|title=flightglobal: ''France seeks EFA radar share'', 4 April 1987}}</ref>

Ferranti presented its ECR-90, based on the [[Blue Vixen]], as early as 1986, while AEG offered the MSD-2000 "Emerald", which was based on the [[AN/APG-65 radar family|AN/APG-65]].<ref>[http://www.flightglobal.com/FlightPDFArchive/1986/1986%20-%202305.PDF flightglobal: ''EFA radar battle: new versus now'', 6 September 1986] (PDF; 2,4&nbsp;MB)</ref> Ferranti's main argument was that a European fighter aircraft should also be equipped with a European radar. Ferranti had already been working with Thompson-CSF, [[Indra Sistemas|Inisel]] and FIAR on the development of the radar since 1983. France withdrew with Thompson-CSF in June 1985, followed a year later by AEG. AEG wanted to offer a system based on the APG-65, as the company already had the production licence for this. There was still speculation as to whether [[Thorn EMI|Thorn-EMI]] would offer the [[AN/APG-68]], but this did not end up happening. Both bidders submitted two-part offers: one that fully met the tender requirements and a reduced low-cost variant. Ferranti and FIAR offered the ECR-90 and the Super Vixen, AEG and GEC Marconi the MSD-2000 and the APG-65, but both high-tech offers were too expensive and the low-cost alternatives were deemed insufficient.

As a result, a new tender was launched. This time, the performance requirements were slimmed down and the manufacturers were also asked how the costs could be reduced. The requirements were also less stringent in order to fuel the inventive spirit of the engineers.<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1988/1988%20-%200240.html|title=flightglobal: ''Teams try again on EFA radar'', 30 January 1988}}</ref> The two new tenders were submitted in February 1988:<ref name="ff">{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1988/1988%20-%200661.html|title=flightglobal: ''EFA radar: heads or tails, the UK loses'', 19 March 1988}}</ref>

* '''ECR-90:''' The European Collaborative Radar 90 was offered by Ferranti in the variants -90, -90A and -90B. The detection range was always the same, only the capabilities were to be integrated bit by bit. The main argument was again that the radar would account for a significant proportion of the costs of the EFA, and thus a European in-house development would enable higher added value in Europe. To reduce risk, the ECR-90 was to be based on the Blue Vixen of the [[British Aerospace Sea Harrier|BAE Sea Harrier]] FA2, which was already [[AIM-120 AMRAAM|AMRAAM]]-capable in order to send target updates to the missiles. For the Blue Vixen, two planar antenna designs were tested: one made of a light metal alloy and one formed from an  aluminised carbon fibre plate; the latter was rejected due to the higher costs and uncertainty regarding durability. The choice was left open for the ECR-90. The antenna drive was based on the Blue Vixen and PS-05 of the Saab 39, and corrected pitch and roll movements with 0.5&nbsp;hp samarium-cobalt motors. There was no roll control: roll angles were compensated electronically. The coupled-cavity travelling wave tube was to be supplied by [[Selenia (company)|Selenia]] or Thomson-CSF. The signal processing and processors were taken over from the Blue Vixen. Since the software development of Blue Vixen accounted for about 80% of the development costs, and about 50% of the software for the ECR-90 was to be taken over, savings opportunities were seen here.  Blue Vixen only had 11 of the required 31 radar modes. The 32-bit signal processor, however, was to be twice as fast and supplied by Hughes, [[IBM]] or [[Ericsson]]. The Blue Vixen's D80 achieved around 500 [[Instructions per second|MIPS]]. The computing modules were housed in metal cassettes that acted as heat sinks and had air flowing through the centre. While the Blue Vixen consisted of 13,790 parts, the ECR-90 was to consist of only 13,000 parts.<ref name="ff" />

* '''MSD-2000:''' The Multimode Silent Radar 2000 from AEG and GEC Marconi was based on the APG-65. This was a logical progression as the APG-65 had been planned for the EFA predecessor TKF-90, which is why the weight, volume and energy specifications of the EFA radar were also adopted from the TKF-90 program. Marconi also came to the conclusion that a new development would not be possible in the time available, which is why the APG-65 of the [[McDonnell Douglas F/A-18 Hornet|F-18]] was accepted as the base model. The APG-65 already had 28 of the required 31 radar modes and the AMRAAM capability, meaning that 80% of the software could be adopted. A further 10% had to be reprogrammed and another 10% newly programmed. The additional programming related almost exclusively to the three missing modes "Non-Cooperative Target Recognition", "Visual Identification" and "Slaved air-to-air acquisition". In addition, the number of targets in [[Track while scan|TWS]] mode and the ECCM capability were to be improved. Compared to the APG-65, the antenna was to be enlarged from 68&nbsp;cm to 75&nbsp;cm and the radiation power doubled. The receiver sensitivity was to be increased, the antenna was to be equipped with D/F-band dipoles for a NATO [[Identification friend or foe|IFF]] system, and the signal processor was to be replaced with a faster model from Marconi. New samarium-cobalt motors were planned for the antenna drive so as not to reduce the antenna speed. Although the transmitter power was to be doubled compared to the APG-65, the transmission power was always to be kept as low as possible to prevent detection. The number of plug-in cards was to be reduced from 21 to 7, but 25% of the computing and memory capacity was to remain free. The remaining 17 free slots would then be available for expansion. The radar processor was to be adopted from the [[AI.24 Foxhunter]] radar of the [[Panavia Tornado ADV|Tornado ADV]], which was based on a 32-bit [[Motorola 68020]], in order to double the computing power. In total, less than 15% of the radar would come from the US.<ref name="ff" />

The radar software was to be programmed in [[Ada (programming language)|Ada]], as was the entire EFA software.<ref name="ff" /> The US was rather critical of the required technology transfer for the MSD-2000 when it was negotiated in May 1988,<ref>[http://www.flightglobal.com/FlightPDFArchive/1988/1988%20-%201399.PDF flightglobal: ''US hampers EFA radar bid'', 28 May 1988] (PDF; 2,3&nbsp;MB)</ref> but nevertheless agreed to it in August of that year. The schedule now envisaged completing the first airworthy radars in 1992, as the first flight of the EFA was planned for 1991, and starting series production in 1996. Spain was now in favour of the MSD-2000, as the cost and timeframe seemed the most realistic.<ref>[http://www.flightglobal.com/FlightPDFArchive/1988/1988%20-%202244.PDF flightglobal: ''EFA radar transfer agreed'', 27 August 1988] (PDF; 2,2&nbsp;MB)</ref> After October 1988, the decision was made,<ref>[http://www.flightglobal.com/FlightPDFArchive/1988/1988%20-%203049.PDF flightglobal: ''EFA radar choice nears'', 22 October 1988] (PDF; 285&nbsp;kB)</ref> with Ferranti's ECR-90 winning the race but not being chosen.

Since Germany did not agree with the decision, [[List of German defence ministers|German Defence Minister]] [[Gerhard Stoltenberg]] met with British [[Secretary of State for Defence|Defence Secretary]] [[Tom King, Baron King of Bridgwater|Tom King]] in mid-1989.<ref name=":3">{{cite news |last=Miller |first=Charles |date=1990-05-08 |title=Radar Deal Keeps Britain in Forefront of Airborne Technology |publisher=The Press Association Ltd.}}</ref> They agreed to commission a study into whether the MSD-2000 could be adapted to British requirements after all. At the same time, the UK Ministry of Defence launched a study into how the partner countries, excluding Germany, could develop their own radar for the EFA.<ref>[http://www.flightglobal.com/FlightPDFArchive/1989/1989%20-%203013.PDF flightglobal: ''EFA – UK looks at three-nation radar'', 7 October 1989] (PDF; 1,3&nbsp;MB)</ref> The MSD-2000 study was negative, but Germany still refused to give in on this issue. As no agreement could be reached after 18 months, the UK and Germany called on the industry to find a solution. In December 1989, Ferranti held talks with Telefunken System Technik (formerly AEG until Daimler took over the company) to co-operate on the ECR-90 and resolve the German resistance. At the same time, the industry warned politicians of rising costs due to the delays. Eurofighter GmbH then sent letters to all four partner countries and [[NATO Eurofighter and Tornado Management Agency|NETMA]] stating that all additional costs would be passed on to them. This was important as the EFA radar was to be awarded as a [[fixed-price contract]] and the companies involved were to be reimbursed for the delays.<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1989/1989%20-%203776.html|title=flightglobal: ''Ferranti rival in talks to join ECR-90 project'', 6-12 December 1989}}</ref> At the beginning of 1990, GEC Marconi, which was working on the MSD-2000, swallowed up Ferranti, which was designing the ECR-90, a decision that was underwritten by the British government.<ref name=":3" /> Ferranti's labs became the new GEC Ferranti in 1990, and then [[BAE Systems Avionics]] when GEC's various military electronics divisions - Ferranti, [[Marconi Company|Marconi]] and [[Elliott Brothers (computer company)|Elliott Brothers]] - were merged. [[Plessey]], which manufactured the EFA's missile detectors, was taken over by a consortium of GEC Marconi and [[Siemens]]. This signalled a relaxation on the radar front.<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1990/1990%20-%200220.html|title=flightglobal: ''Ferranti take-over cuts UK MoD options'', 6 February 1990}}</ref> In early 1990, GEC-Ferranti was finally declared the winner of the EFA radar competition and awarded a £300m contract. In mid-1990, GEC-Ferranti negotiated with Ericsson to remove the company from the ECR-90 Euroradar consortium and use the Motorola 68020 processors of the MSD-2000 instead. In a comparison, its signal processing proved to be significantly more powerful. This in turn was seen as a problem by Germany, as the redesign of the ECR-90 meant that delays and further cost increases were unavoidable.<ref>{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1990/1990%20-%201986.html|title=flightglobal: ''Ericsson ousted from EFA radar'', 24 July 1990}}</ref>

Hughes sued GEC for $600 million for its role in the selection of the EFA and alleged that it used Hughes technology in the ECR-90 when it took over Ferranti. It later dropped this allegation and was awarded $23 million; the court judged that the MSD-2000 "had a real or substantial chance of succeeding had GEC not [tortiously] intervened{{nbsp}}... and had the companies, which were bound by the Collaboration Agreement, faithfully and diligently performed their continuing obligations thereunder to press and promote the case for MSD-2000."<ref>{{cite news | title=Court finds GEC 'intervened' on behalf of onetime EFA rival Ferranti | work = Aerospace Daily | publisher = McGraw-Hill Inc. | page = 398 | date = 1994-03-15}}</ref>

Since these events, further mergers have taken place in the industry. Parts of BAE Systems Avionics were merged with Galileo Avionica to form [[SELEX Galileo]] in 2005 which in turn then merged with other [[Finmeccanica]] defence electronics companies in 2013 to create [[Selex ES]] (merged in turn in Finmeccanica, rebranded [[Leonardo S.p.A.|Leonardo]] since 2017). The development effort is now organized under the Euroradar consortium, consisting primarily of [[Selex ES]],<ref name="fg_captor-e">{{cite web|url=http://www.flightglobal.com/articles/2010/07/15/344416/eurofighter-nations-offered-aesa-radar-enhancement.html|title=Eurofighter nations offered AESA radar enhancement |date=15 July 2010|first=Craig |last= Hoyle|work=[[Flightglobal]]}}</ref> as well as [[Airbus]] and [[Indra Sistemas|Indra]].

The ECR-90 was renamed CAPTOR when the project passed the production contract milestone.<ref>{{cite web|url=http://eurofighter.airpower.at/sensorik-captor.htm|title=Eurofighter Typhoon|work=airpower.at|accessdate=18 November 2015|language=de}}</ref>

===Captor-E AESA variant ===
[[File:Tr-module.jpg|thumb|TR-Module]]
In 1993 a European research project was launched to create the Airborne Multirole Solid State Active Array Radar (AMSAR); it was run by the British-French-German GTDAR ("GEC-Thomson-[[DASA]] Airborne Radar") consortium (now [[Selex ES]], [[Thales Group|Thales]] and [[Airbus]] respectively).<ref name="janes">{{cite news |date=June 1, 2013  |title=The Three Musketeers: Europe's next-gen fighter radars |newspaper=Jane's International Defense Review}}</ref> This evolved into the CAESAR (Captor Active Electronically Scanned Array Radar), now known as Captor-E [[active electronically scanned array]].<ref name="janes"/>

In May 2007, Eurofighter Development Aircraft 5 made the first flight with the a prototype of the Captor-E.<ref name="leonardo_captor">{{cite web|url=http://www.leonardocompany.com/-/captor-e-radar|title=Radar Captor-E|publisher=[[Leonardo S.p.A.|Leonardo]]}}</ref> The Captor-E is based on the Captor radar currently in service on Eurofighter production aircraft. The new generation of radar is intended to replace the mechanically steered antennas and high-power transmitters used on current Eurofighter aircraft with an electronically steered array. This enables new mission capabilities for combat aircraft such as simultaneous radar functionalities, air surveillance, air-to-ground and weapon control. The new radar improves the effective [[air-to-air missile]] range of the aircraft and allows for faster and more accurate detection and tracking of multiple aircraft with lower life cycle costs.<ref name="leonardo_captor"/> In July 2010, it was reported that the Euroradar consortium made a formal offer to provide an AESA solution for the Eurofighter. The consortium plans to retain as much "back-end" equipment as possible while developing the new radar and also stated that the inclusion of an AESA radar was an important in securing orders from foreign nations.<ref name="leonardo_captor"/>

On 19 November 2014, at the Edinburgh office of [[Selex ES]], the European consortium Eurofighter GmbH and the inter-governmental agency NETMA (NATO Eurofighter and Tornado Management Agency) signed a contract worth €1 billion to develop the electronically scanned [[digital antenna array]] Captor-E radar for the Typhoon.<ref>{{cite news|url=https://www.bbc.co.uk/news/uk-scotland-scotland-business-30114054|title=Eurofighter radar deal secures 500 jobs in Edinburgh|work=BBC News|date=19 November 2014 |accessdate=18 November 2015}}</ref>

Characteristics of the antennas:

* Captor-M: Mechanically scanned antenna. Interface and integration of the radar to the aircraft by [[BAE Systems]]
* Captor-E ECRS Mk0:  Interface and integration of the radar to the aircraft by [[BAE Systems]].<ref name=":0">{{Cite web|url=https://www.hensoldt.net/fileadmin/HENSOLDT_2019/Products/Radar_IFF_Datalink/0717_14_Captor_E.pdf|title=Wayback Machine|website=www.hensoldt.net}}</ref> AESA antenna, the [[Transceiver|T/R modules]] are made with [[Gallium arsenide|GaAs]] HEMT HPA ([[gallium arsenide]] [[High-electron-mobility transistor|High Electron Mobility Transistor]] [[High-power amplifier|High Power Amplifiers]])
* Captor-E ECRS Mk1: Interface and integration of the radar to the aircraft by [[Airbus Germany]].<ref name=":0" /> AESA antenna, the [[Transceiver|T/R modules]] are made with [[Gallium nitride|GaN]] HEMT HPA ([[gallium nitride]] [[High-electron-mobility transistor|High Electron Mobility Transistor]] [[High-power amplifier|High Power Amplifiers]]).<ref>{{Cite web |date=2024-02-25 |title=The Eurofighter’s AESA radars – Defense Archives |url=https://web.archive.org/web/20240225084309/https://defensearchives.de/editorials/the-eurofighters-aesa-radars/ |access-date=2025-04-18 |website=web.archive.org}}</ref>
* Captor-E ECRS Mk2: Interface and integration of the radar to the aircraft by [[BAE Systems]].<ref name=":0" /> AESA antenna, the [[Transceiver|T/R modules]] are made with [[Gallium arsenide|GaAs]] and [[Gallium nitride|GaN]] [[High-electron-mobility transistor|HEMT]] HPA (gallium arsenide and gallium nitride High Electron Mobility Transistor High Power Amplifiers). This enables efficient multi-tasking of radar tracking use and electronic warfare simultaneously.<ref>{{Cite web |date=2023-04-21 |title=Le premier radar ECRS MK2 ! |url=https://www.avianews.ch/post/le-premier-radar-ecrs-mk2 |access-date=2023-06-21 |website=Avia news |language=fr}}</ref>  It is installed on a pivot derived from the one used on the [[Saab JAS 39 Gripen|Gripen E]] with the [[Selex ES|Selex]] ES-05 Raven radar. The wider bandwidth meant that a new radome was needed.<ref>{{Cite web |last=Lake |first=Jon |title=Britain's Long-awaited Radar Two Program Breaks Cover |url=https://www.ainonline.com/aviation-news/defense/2020-09-14/britains-long-awaited-radar-two-program-breaks-cover |access-date=2023-06-21 |website=Aviation International News}}</ref>

== Technology ==
{{Proofreader needed|EuroRADAR CAPTOR|de|date=February 2024}}
The CAPTOR was optimised for [[Aerial warfare|air combat]] with [[Beyond-visual-range missile|beyond visual range]] [[air-to-air missile]]s (BVRAAM) under strong enemy [[electronic countermeasure]]s, resulting from the requirements of the [[Cold War]].<ref name="janes2">http://www.janes.com/articles/Janes-Avionics/Captor-Radar-International.html {{Bare URL inline|date=August 2024}}</ref><ref name="flight_how">{{Cite web|url=http://www.flightglobal.com/pdfarchive/view/1986/1986%20-%202648.html|title=Flightglobal: ''Eurofighter avionics: how advanced?'', 4 October 1986}}</ref> Since the end of the Cold War, the main focus of the Eurofighter has shifted from [[Fighter aircraft|fighter]] to [[Multirole combat aircraft|multi-role]] combat aircraft tasks. The [[Close air support|ground attack]] capabilities of the radar were therefore further developed in this direction. The mechanical control system was selected in the initial phase of the Eurofighter project as the development risks were to be minimised. According to the project managers, the technology of a mechanically swivelled antenna were fully exploited in the CAPTOR.<ref name="aviation">{{cite web |url=http://www.aviationtoday.com/av/issue/feature/Avionics-Crown-Typhoon-Performance_1048.html |archive-url=https://web.archive.org/web/20150402155531/http://www.aviationtoday.com/av/issue/feature/Avionics-Crown-Typhoon-Performance_1048.html#.VR1meezP32c |title=Aviation Today: ''Avionics Crown Typhoon Performance'' |date=2006-08-01 |archive-date=2015-04-02 }}</ref>

The radar consists of a mechanically controlled antenna made of [[Carbon-fiber-reinforced polymers|carbon fibre-reinforced plastic]] with a diameter of {{convert|0.7|metre}}.<ref name="flight_how" /><ref name="finest">{{Cite web |url=http://www.aviationtoday.com/av/categories/military/Typhoon-Europes-Finest_917.html |title=Avionics Magazin: ''Typhoon: Europe's Finest'' |access-date=February 1, 2024 |archive-date=April 27, 2010 |archive-url=https://web.archive.org/web/20100427125345/http://www.aviationtoday.com/av/categories/military/Typhoon-Europes-Finest_917.html |url-status=dead }}, 1 June 2003.</ref> The antenna can be swivelled by ±60° in elevation and +-70° [[azimuth]]. Four high-precision [[samarium-cobalt]] [[servomotor]]s with high torque are used to control the antenna in order to achieve high scanning speeds.<ref name="sensor">{{Cite web |url=http://typhoon.starstreak.net/Eurofighter/sensors.html |title=starstreak.net: ''Sensors'' |access-date=November 30, 2010 |archive-date=November 27, 2014 |archive-url=https://web.archive.org/web/20141127103445/http://typhoon.starstreak.net/Eurofighter/sensors.html |url-status=bot: unknown }}, retrieved 26 July 2013.</ref> The motors can only move the planar antenna in elevation and azimuth angles while roll angles are compensated electronically by combined control in order to reduce weight. Due to the very high scanning speed for a mechanically swivelled antenna, the radar can also interleave different radar modes, which would only otherwise be possible with phased array antennas, albeit much faster. For example, air-to-air and air-to-ground modes can be combined in one scan pass.<ref name="sensor" /><ref name="finest" /> The accuracy is less than one [[milliradian]] in alignment and less than {{convert|10|metres}} in distance.<ref>{{Cite web |url=http://www.raeng.org.uk/prizes/macrobert/finalists/2000/bae.htm |title=RAeng: ''BAE Systems Sensor Systems Division for their CAPTOR Radar for the Eurofighter'', 2000 Finalist |access-date=February 1, 2024 |archive-date=August 28, 2008 |archive-url=https://web.archive.org/web/20080828165907/http://www.raeng.org.uk/prizes/macrobert/finalists/2000/bae.htm |url-status=dead }}</ref>

The CAPTOR operates in the [[X-band]] from 8 to 12&nbsp;[[hertz|gigahertz]] (GHz) ([[Polarization (waves)|horizontally polarised]]) and has twice the [[electric power transmission|transmission power]] of the [[AN/APG-65 radar family|AN/APG-65]].<ref name="sensor" /> It automatically switches between low, medium and high [[Pulse-repetition frequency|pulse repetition rate]]s.<ref name="flight_how" /> These range from 1,000 to 200,000 pulses per second, with the main focus on medium pulse repetition rates. [[Identification friend or foe|Friend or foe detection]] (IFF) is integrated into the radar unit and is normally fully automatic. The signal processing consists of 61 plug-in cards (shop replaceable items-SRI) and 6 line replaceable units. The modular design allows for easy repairs and upgrades. The built-in self-diagnostic capability indicates the defective SRI, which can be read out on the ground by a laptop without having to switch on the power supply. If the SRI is actually defective, it is replaced.<ref>Prof. John F. Roulston: ''Cost Drivers in Airborne Fighter Radar Programmes'', The Future of Radar in the UK and Europe (Ref. No. 1999/186), IEE Workshop, 1999.</ref> The software was written in Ada in accordance with the [[MIL-STD-2167|MIL STD 2167A]] standard.<ref name="finest" /> The CAPTOR is the first NATO radar with three processing channels. The first channel is used for target search, the second for target tracking and identification and the third for localisation, classification and overcoming jamming as well as [[Sidelobes|sidelobe]] suppression.<ref name="janes2" /> The entire system weighs {{convert|193|kg}} and the computers are cooled with both liquid and air.<ref name="janes2" />

=== Signal processing ===
Due to the [[sensor fusion]] used in the Eurofighter Typhoon by means of the Attack and Identification System (AIS), the radar modes are normally selected automatically by the on-board computer; the CAPTOR is operated exclusively according to the VTAS principle (VTAS - Voice, Throttle and Stick).<ref name="truppe">{{Cite web|url=http://www.bmlv.gv.at/truppendienst/ausgaben/artikel.php?id=807|title=Bundesheer - TRUPPENDIENST - Ausgabe 6/2008 - Der Eurofighter "Typhoon" (VII)}}</ref><ref name="sensor" /> The general mode of operation of the radar is as follows: First, the radar transmits in 'Velocity Search' (VS) mode to detect approaching targets even in [[ground clutter]]. If targets are detected, the radar switches to 'range while search' (RWS) mode. The computer creates a track file and continues to work in '[[track while scan]]' (TWS) mode while searching for new targets. The identity of the targets is then determined by NIS or NCTI and the threats are prioritised. Further modes such as Raid Assessment and Threat Assessment<ref name="flight_how" /> are then applied if necessary. Further operating modes and capabilities are not listed in full:

* '''Synthetic Aperture Radar / Automatic Target Recognition:''' Older aircraft types also have a [[synthetic aperture radar]] (SAR) mode, but the pilot must search for targets himself, provided the resolution of the image is high enough. This function is automated in the CAPTOR-D/E. The high-resolution SAR image is first smoothed with a [[Gaussian filter]] to reduce details. Then the gradient and the direction of the gradient to the neighbouring pixel is determined starting from each pixel. If the magnitude of the gradient of a pixel in a certain direction is greater than that of the neighbouring pixel, the pixel is declared an edge, otherwise it is assigned to the background. Weak edges are eliminated by a [[hysteresis]] threshold ([[Canny edge detector|Canny algorithm]]). After another algorithm has generated closed structures, the invariant Fourier descriptors of the image are calculated and fed into an [[artificial neural network]] for automatic target identification.<ref>Heiko Seidel; Christoph Stahl; Frode Bjerkeli; Paal Skaaren-Fystro: ''Assessment of COTS IR image simulation tools for ATR development'', 19 May 2005; SPIE [[doi:10.1117/12.602461]].</ref> Here, several subnets run in parallel and the final result between the subnets is determined by voting.<ref>[http://thesai.org/Downloads/Volume3No8/Paper_16-Automatic_Aircraft_Target_Recognition_by_ISAR_Image_Processing_based_on_Neural_Classifier.pdf F. Benedetto, F. Riganti Fulginei, A. Laudani, G. Albanese: ''Automatic Aircraft Target Recognition by ISAR Image Processing based on Neural Classifier'', (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 3, No.8, 2012] (PDF; 568&nbsp;kB)</ref> The positions of the detected targets are then marked on the SAR image with red diamonds and the target type is displayed in red text above the diamond, e.g. "[[T-72]]" or "[[MLRS]]" (multiple rocket launcher). The generated radar image is superimposed on a vectorised map with known [[Global Positioning System]] (GPS) coordinates stored in the computer in order to calculate the GPS data of the targets. Alternatively, the GPS target position can be determined using the user's own GPS position and different recording angles and distances. To train the neural network, EADS developed software in which [[computer-aided design]] (CAD) models of targets are placed on a map and the scene is converted into a SAR image. The algorithm then attempts to detect the targets despite interfering objects, different target angles and partial occlusion of the targets.<ref>{{Cite web|url=http://www.airpower.at/news04/1114_pt/|title=Precision Targeting für den Eurofighter|website=www.airpower.at}}</ref><ref>{{Cite web |url=http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA471132 |title=EADS: ''Generation of Synthetic SAR Imagery for ATR Development'', RTO-MP-SET-096, 2005 |access-date=February 1, 2024 |archive-date=July 28, 2013 |archive-url=https://web.archive.org/web/20130728120852/http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA471132 |url-status=bot: unknown }}</ref>

* '''Non Cooperative Target Identification:''' Radars have generally been capable of jet engine modulation (JEM) since the end of the 1980s, but this only works in the front of the aircraft as the turbine must be visible. The implementation of 'High Range Resolution' (HRR) was planned for the next generation of fighter aircraft radars. As the name High Range Resolution suggests, the target is profiled along its length. For this purpose, a series of narrowband nanosecond pulses are emitted to achieve a high range resolution in the metre range. In addition to this standard method, it is also possible to transmit narrowband [[chirps]] with stepped [[carrier frequencies]] as a continuum. The former was already possible before 1987, the latter was newly developed by BAE Systems. The method used by CAPTOR is a secret, but it is probably the latter. The radar echo of the target then emits a characteristic frequency curve over time, as a pulse is first reflected by the nose, cockpit canopy, air intake, leading edges of the wings and vertical stabiliser (if the target is irradiated from the front). In general, a bandwidth of 400&nbsp;MHz and a large number of measurements are considered necessary to identify airborne targets. Together with the track data of the target, which is required to determine the angle of the target to the radar, the characteristic frequency curve of the echo over time can be assigned to a target type by means of a database comparison.<ref name="ncti">{{Cite web |url=http://ftp.rta.nato.int/public//PubFullText/RTO/MP/RTO-MP-SET-080///MP-SET-080-$$ALL.pdf |title=NATO RTO: ''Target Identification and Recognition using RF Systems,'' MP-SET-080, October 2004 |access-date=February 1, 2024 |archive-date=June 10, 2015 |archive-url=https://web.archive.org/web/20150610201341/http://ftp.rta.nato.int/public//PubFullText/RTO/MP/RTO-MP-SET-080///MP-SET-080-$$ALL.pdf |url-status=bot: unknown }}</ref> The pilot is then shown an abbreviation for the aircraft type on the display, e.g. "[[Dassault Mirage III|Mrg3]]" or "[[Sukhoi Su-27|Flkr]]". To prevent the size of the database from getting out of hand, only the aircraft type data that is expected to occur in the respective area is loaded for each mission.<ref name="airp">[http://eurofighter.airpower.at/sensorik-captor.htm airpower.at: ''Das "Captor" Radar''], Accessed on 26 July 2013.</ref> Since the outboard load configuration of the target is not known, there may be difficulties with non-cooperative target identification. In this case, hundreds of HRR profiles of the target are created in order to filter out the echoes of the external loads and calculate an ISAR image from them. However, this requires the target to move relative to the radar and the radar to remain on the target for a long time, which is tactically unfavourable.<ref name="ncti"/> The ISAR image can presumably be shown to the pilot in "Visual Identification" mode on the displays, the resolution per pixel dot is lower than with [[Eurofighter Typhoon|PIRATE]].

* '''Space-Time Adaptive Processing / Combat Search:''' This capability is at the heart of the CAPTOR-E. With [[Space-time adaptive processing|Space-Time Adaptive Processing]] (STAP), slow-flying targets can also be recognised under the influence of clutter and interference radiation, even if their echo signal would otherwise be drowned out by interference signals. Several sub-apertures are used for this purpose, with which the wave field reflected from the ground is scanned with a time delay. Ideally, the signals in the individual channels only differ by this time offset. However, moving targets with a [[radial velocity]] component change their distance to the sensor within this period of time, so that the signals are subject to a [[Phase (waves)|phase shift]] and can be distinguished from the clutter signals. In the environment of the echo signal of a target, not only the temporal change is considered, but also compared with the spatial change (space-time).<ref>[http://www.radartutorial.eu/20.airborne/ab11.de.html Radartutorial: ''Space-Time Adaptive Processing (STAP)''], retrieved 22 July 2013.</ref> The principle is also used to detect slow ground targets in [[Moving target indication|Ground Moving Target Indication]] (GMTI) mode.<ref name="amsar">Milin, Moore, Bürger, Triboulloy, Royden, Gerster: ''AMSAR – A European Success Story in AESA Radar'', Radar Conference – Surveillance for a Safer World, 12–16 October 2009.</ref> If an aerial target is lost in TWS mode, the suspected target area no longer has to be swivelled in a time-consuming manner with a signal lobe: The Combat Search mode generates multiple signal lobes that cover the target area in a chessboard-like manner within an angle range of 20° × 20°. Idealised, one pulse, sent and received by several signal lobes, is sufficient to find the lost target again.<ref name="roulston">Prof. John Roulston / Filtronic, BAE Systems: ''Future developments in Airborne Radar'', Institution of Electrical Engineers 2006.</ref>

* [[File:Adaptive_Beam_Forming2.jpg|thumb|Adaptive Beam Forming]]'''Jammer Mapping / Deterministic Nulling:''' The CAPTOR-E (according to rumours also the CAPTOR-M) is capable of jammer mapping. This uses spectral processing to determine the identity and angle of the jammer with a high degree of accuracy. The CAPTOR-E then starts with digital adaptive [[beamforming]]: as the [[directivity]] of an AESA antenna can be manipulated as required by controlling the transmit/receive (T/R) modules, zeros are set in the [[Radiation pattern|antenna pattern]] in the direction of the jammers.<ref name="roulston" /> The key is to make the null points as narrow as possible so that targets next to interferers can be reliably recognised. During AMSAR flights, the signal strength of interference sources could be reduced to background noise so that targets reappeared.<ref>Wolfgang Holpp / EADS: ''The New Generation of European E-Scan Fighter Radars'', Microwave Symposium Digest (MTT) / 2010 IEEE MTT-S International, 23–28 May 2010.</ref> Deterministic nulling is used to improve the result. Here, the received signals of the T/R modules are weighted differently by the signal processor across all degrees of freedom of the antenna in order to further reduce the influence of interference.<ref name="amsar" />

* '''Low Probability of Intercept:''' In order to reduce the probability of detection by enemy radar detectors and electronic support measures, the CAPTOR-E will be equipped with an [[Low-probability-of-intercept radar|low-probability-of-intercept]] (LPI) radar  operating mode. Few details are known about this; the radar will transmit with a wide main lobe and receive through multiple lobes with high antenna gain.<ref name="roulston" />

* '''Noise Jamming / High-Power Microwave:''' When used as a jammer, the radar transmits at full power in all frequencies simultaneously, focussing the radar energy on the enemy's X-band antenna. This increases the background noise at the target radar, the [[signal-to-noise ratio]] deteriorates and the range decreases. If the available [[effective radiated power]] (ERP) of their own antenna is high enough, additional signal lobes can be formed for airspace search, target tracking or interference. If the burn-through distance is undershot, the broadband noise becomes pointless. If the enemy is close enough to the CAPTOR-E, High-Power Microwave (HPM) mode comes into effect: the radar energy is focussed extremely strongly on the target and the transmission frequency, pulse repetition rate and signal pattern are adapted to the target. The energy penetrates the object via a front-door, usually the weapon's seeker (IR or radar), or via feedback effects from the surface and openings (back-door). This creates an electromagnetic field inside, which - if suitable transmission parameters are selected - interferes with the weapon's electronics. This leads to an increase in the [[bit error rate]] and, in the best case, to computer crashes.<ref>Diverses, z.&nbsp;B. [http://www.ece.unm.edu/summa/notes/SDAN/0037.pdf WIS u.&nbsp;a.: ''Susceptibility of Some Electronic Equipment to HPEM Threats''](PDF; 1,1&nbsp;MB) oder {{Webarchive|url=https://web.archive.org/web/20100726103538/http://www.ece.unm.edu/summa/notes/SDAN/0037.pdf |date=2010-07-26}} (PDF; 4,2&nbsp;MB)</ref> Possible applications include the deflection of enemy missiles and [[suppression of enemy air defences]] (SEAD).<ref name="hpm">{{Cite web |url=http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA335582 |title=AGARD / Nitsch u. a.: ''High-Power Microwaves Effects on Smart Electronic Weapon Systems'', 14–17 April 1997 |access-date=1 February 2024 |archive-date=28 July 2013 |archive-url=https://web.archive.org/web/20130728120905/http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA335582 |url-status=bot: unknown }}</ref> While the jammer function should be available as soon as possible with the introduction of the CAPTOR-E,<ref name="pano2">PANORAMA DIFESA: Typhoon continua a crescere, GIUGNO 2013.</ref> its use as an [[Directed-energy weapon|energy weapon]] is not planned until later.<ref name="5gen">{{Cite web |url=http://www.eurofighter.com/fileadmin/web_data/downloads/extpub/02_5thGenFighter.pdf |title=Eurofighter World: ''What is a 5th Generation Fighter?'', 2/2010 |access-date=February 1, 2024 |archive-date=November 2, 2012 |archive-url=https://web.archive.org/web/20121102122645/http://www.eurofighter.com/fileadmin/web_data/downloads/extpub/02_5thGenFighter.pdf |url-status=dead }} (PDF; 773&nbsp;kB)</ref>

* '''High-Speed Datalink / Cyberattack:''' AESA antennas can also be used as directional radio antennas to transmit data at high data transmission rates. For example, the [[AN/APG-77]] can transmit at 548 [[megabits per second]] and receive in the gigabit range.<ref>{{Cite web|url=http://www.theregister.co.uk/2007/06/19/super_stealth_jet_acts_as_flying_wifi_hotspots/|title=F-22 superjets could act as flying Wi-Fi hotspots • The Register}}</ref> As the CAPTOR-E uses the same carrier frequency, similar speeds will be possible. The data transmission function should be available shortly after the CAPTOR-E is launched.<ref name="pano2" /> Its use as a cyber weapon for injecting malware is only planned for later.<ref name="5gen" /> The Suter, which was developed by BAE Systems to attack enemy computer networks and communication systems, means that the EuroRADAR consortium already has expertise and experience.

* '''Bistatic Radar / Space-Based Radar:''' The ability to exchange [[data packets]] between radars makes it possible to use two CAPTOR-Es as [[bistatic radar]]s.<ref name="captor-e">[http://www.selex-es.com/~/media/Files/S/Selex-Galileo/products/air/fire-control-radar/CAPTOR-E-02-2013.pdf EuroRADAR: ''CAPTOR-E''] (PDF; 531&nbsp;kB), retrieved 25 July 2013.</ref> Thanks to the inclined, rotatable antenna surface, the machines can fly on a parallel course while working together. One exotic possible application would be to use a satellite with an X-band AESA in orbit as a transmitter and utilise the CAPTOR-E as a [[passive radar]]. The principle was already demonstrated in November 2007 with the [[TerraSAR-X]] satellite.<ref name="bi">[http://elib.dlr.de/55400/1/RoBaKrMo_TGRS10_ieee.pdf Rodriguez-Cassola, V. Baumgartner, Krieger: ''Bistatic TerraSAR-X/F-SAR Spaceborne–Airborne SAR Experiment: Description, Data Processing, and Results'', IEEE Transactions On Geoscience and Remote Sensing, VOL. 48, NO. 2, February 2010] (PDF; 3,0&nbsp;MB)</ref> The successor system to [[SAR-Lupe]], called SARah, is also to receive a satellite with AESA, which is based on TerraSAR-X and [[TanDEM-X]].<ref>{{Cite web |url=https://www.ohb-system.de/pressemitteilungen-details/items/ohb-system-ag-erhaelt-auftrag-fuer-entwicklung-und-bau-des-radarsatelliten-aufklaerungssystems-sarah-fuer-die-deutsche-bundesweh.html |title=OHB System: ''OHB System AG erhält Auftrag für Entwicklung und Bau des Radarsatelliten-Aufklärungssystems SARah für die deutsche Bundeswehr'', 2 July 2013 |access-date=1 February 2024 |archive-date=4 May 2014 |archive-url=https://web.archive.org/web/20140504002222/https://www.ohb-system.de/pressemitteilungen-details/items/ohb-system-ag-erhaelt-auftrag-fuer-entwicklung-und-bau-des-radarsatelliten-aufklaerungssystems-sarah-fuer-die-deutsche-bundesweh.html |url-status=dead }}</ref> For example, the [[Defence Evaluation and Research Agency]]'s (DERA) AESA radar prototype 'Phased Array Concepts Evaluation Rig' (PACER), which was intended to support the development of the AMSAR, consisted only of passive X-band receiver modules and was intended to research bistatic applications, among other things.<ref>DERA / Richardson u.&nbsp;a.: ''[https://ieeexplore.ieee.org/document/858988 PACER (Phased Array Concepts Evaluation Rig): Design, Development and Adaptive Beamforming Experiments]'', IEEE International Conference on Phased Array Systems and Technology, 2000. {{ISBN|0-7803-6345-0}}</ref>

== Operators ==

=== Current operators ===

==== Captor-M ====
'''571''' aircraft fitted with this radar.

{{AUT}}

* [[Austrian Air Force]] – 15 radars and 3 ordered (Tranche 1)<ref>{{cite web |date=4 October 2022 |title=Drei neue Eurofighter für das Heer |url=https://www.diepresse.com/6198418/drei-neue-eurofighter-fuer-das-heer |work=Die Presse |language=de}}</ref>

{{DEU}}

* [[German Air Force]] – 143 radars (Tranche 1 - Tranche 3)

{{ITA}}

* [[Italian Air Force]] – 96 radars (Tranche 3)

{{OMN}}

* [[Royal Air Force of Oman]] – 12 radars (Tranche 1 - Tranche 3)<ref>{{cite web |title=Oman completes Typhoon deliveries |url=https://www.timesaerospace.aero/features/defence/oman-completes-typhoon-deliveries |work=Times Aerospace}}</ref>

{{SAU}}

* [[Royal Saudi Air Force]] – 72 radars (Tranche 2 - Tranche 3)

{{ESP}}

* [[Spanish Air and Space Force]] – 73 radars (Tranche 1 - Tranche 3)

{{UK}}

* [[Royal Air Force]] – 160 radars (Tranche 1 - Tranche 3)

==== Captor-E ECRS Mk0 ====
'''52''' aircraft will eventually be fitted with this radar.

{{KWT}}

* [[Kuwait Air Force]] – 6 radars in service, 22 more on order as of September 2022 (Tranche 3)<ref>{{cite web |date=15 December 2021 |title=Take a Look at These Cool Photos of the Delivery Flight of the Kuwait Air Force's First Eurofighter Typhoons |url=https://theaviationist.com/2021/12/15/kaf-typhoons-delivery/ |work=The avionist}}</ref><ref>{{cite web |date=28 September 2022 |title=وصول الدفعة الثالثة من طائرة اليوروفايتر تايفون إلى أرض الوطن |url=https://www.alanba.com.kw/1144102/ |work=Al anba |place=KW |language=ar}}</ref>

{{QAT}}

* [[Qatar Emiri Air Force]] – 10 radars in service, 14 more on order as of March 2023 (Tranche 3)<ref>{{cite web |last=Cenciotti |first=David |date=27 August 2022 |title=First Batch Of Eurofighter Typhoon Aircraft Delivered to Qatar |url=https://theaviationist.com/2022/08/27/first-batch-of-eurofighter-typhoon-aircraft-delivered-to-qatar/ |access-date=19 May 2023 |website=The Aviationist}}</ref><ref>{{cite web |title=Displaying Serials in range ZR |url=https://ukserials.com/results.php?serial=ZR |access-date=19 May 2023 |website=ukserials.com}}</ref>

=== Future operators ===

==== Captor-E ECRS Mk1 ====
Over '''150''' aircraft should eventually be fitted with this radar, some retrofitted.

{{DEU}}

* [[German Air Force]] – 38 radars to equip the Tranche 4 "Quadriga" <ref name=":1">{{Cite web |title=Future proofing the Eurofighter Typhoon. {{!}} HENSOLDT  |url=https://www.hensoldt.net/stories/future-proofing-the-eurofighter-typhoon/ |access-date=2023-06-21 |website=www.hensoldt.net}}</ref> Initial deliveries will be of the Mk 0 radar
* [[German Air Force]] – 110 radars on order for the modernisation of the Tranche 2 and 3 <ref name=":2">{{Cite web |url=https://www.airbus.com/en/newsroom/press-releases/2020-06-airbus-signs-contract-for-integration-of-115-new-eurofighter-escan |access-date=2023-06-21 |website=www.airbus.com |title=Airbus signs contract for integration of 115 new Eurofighter ESCAN radars &#124; Airbus |date=28 October 2021 }}</ref>

{{ESP}}

* [[Spanish Air and Space Force]] – 20 radars to equip the Tranche 4 "Halcon" <ref name=":1" /> Initial deliveries will be of the Mk 0 radar
* [[Spanish Air and Space Force]] – 5 radars on order for the modernisation of the Tranche 3 <ref name=":2" />

==== Captor-E ECRS Mk2 ====
At least '''40''' aircraft will eventually be fitted with this radar, up to 160 aircraft (depending on Germany and the UK's decisions).

{{UK}}  – [[Royal Air Force]]<ref name=":4">{{Cite web |title=First ECRS Mk2 radar for UK Typhoon fleet delivered to BAE Systems for integration |url=https://www.leonardo.com/en/news-and-stories-detail/-/detail/leonardo_raf_ecrs_mk2_delivery |access-date=2023-06-21 |website=www.leonardo.com}}</ref>

* 40 radars on order for the modernisation of the Tranche 3
* Potential order for Tranche 2 (up to 67 aircraft)

=== Potential operators ===
{{DEU}}
* [[German Air Force]] – Discussions to shift from the Mk1 variant to the Mk2 with the 15 (up to 30) Eurofighter ECR that might be new or based on an existing aircraft
* [[German Air Force]] – Discussions to shift from the Mk1 variant to the Mk2 with the Tranche 4 "Quadriga" <ref>{{cite web |date=7 October 2020 |title=Beam Scheme |url=https://www.armadainternational.com/2020/10/beam-scheme/}}</ref>
{{ITA}}<ref>{{Cite web |date=2024-07-07 |title=Italian Air Force to receive 24 new Eurofighters with ECRS Mk2 radar |url=https://defence-industry.eu/italian-air-force-to-receive-24-new-eurofighters-with-ecrs-mk2-radar/ |access-date=2024-07-19 |language=en}}</ref>
* [[Italian Air Force]] – 24 radars (Potential Tranche 4) to be ordered
{{UK}}  – [[Royal Air Force]]<ref name=":4" />
* Potential order for Tranche 2 (up to 67 aircraft)

==References==
{{Reflist}}

==External links==
* [https://electronics.leonardo.com/it/radars-sensors Captor-E Radar] on [https://electronics.leonardo.com/it/radars-sensors Airborne Radar con tecnologia AESA o a scansione meccanica]

[[Category:Aircraft radars]]
[[Category:Ferranti]]
[[Category:Military radars]]