Type 965 radar

{{Short description|Long range aircraft warning radar}} {{Infobox radar | name = Type 965M and Type 965P | image = HMS Coventry (D118) underway c1982.JPEG | caption = HMS ''Coventry'' in 1981; the AKE(2) aerial of her Type 965R radar is at the top of her foremast | country = United Kingdom | introdate =  | number = | type = naval long range aircraft warning radar | frequency = VHF 216-224 MHz | PRF = 200 or 400 p/s nominal | beamwidth = 12° (horizontal), 40° (vertical) | pulsewidth = 3.8 μs and 10 μs | RPM = 10 rpm | range =  | altitude =  | diameter =  | azimuth =  | elevation =  | precision =  | power = 450 kW | other names = }}

The '''Type 965''' radar was VHF (P band) long-range aircraft warning radar used by warships of the Royal Navy from the 1960s onwards. The '''Type 965M''', '''Type 965P''', '''Type 965Q''' and '''Type 965R''' were improved versions; the Type 960, 965M and 965Q used the single bedstead AKE(1) aerial, whilst the Type 965P and 965R used the double bedstead AKE(2) aerial.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}<ref name=BR_333(1)/><ref name=965QR/>

The 965 is ultimately designed to a May 1950 requirement for a further updated version of the 1945 Type 960. The 960 provided long-range early warning on small ships, but had a very wide beam at 35° horizontal. In 1954 the idea of a general-purpose frigate with the ability to provide some fighter direction arose, which required a radar with a much narrower beam. Marconi responded with the 965, reducing the beam to 12°.<ref name=BR_333(1)/><ref>{{citation|url=http://www.rnmuseumradarandcommunications2006.org.uk/960.pdf|title=Type 960 Summary of Data, BR 333(1)|website=www.rnmuseumradarandcommunications2006.org.uk|access-date=3 June 2017}}</ref>{{sfn|Friedman, British Cruisers|page=319 }} Based on WWII technology, the 965 was subject to considerable radar clutter from waves. The Type 965Q and 965R were improvements on the 965M and 965P respectively, adding a COHO-based moving target indication (MTI) mode to suppress clutter.<ref name=965QR/> Designed before the introduction of Doppler filtering, it was not able to detect low-level targets against a background, either landforms or high waves.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

The lack of a true MTI proved to be a serious problem during the 1982 Falklands War, which ultimately led to the loss of {{HMS|Coventry|D118|6}} where Argentine aircraft could not be seen against the background of the islands.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} Similarly, the Type 965 could not detect aircraft flying low;{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} the two Argentine Navy Super Étendards that caused the loss of {{HMS|Sheffield|D80|6}} were not detected by Type 965R radar when they were flying at {{convert|30|m|ft|order=flip}},{{sfnp|Rivas|2012|page=244 }} but were shown as contacts by {{HMS|Glasgow|D88|6}}'s Type 965R radar when they popped up to {{convert|120|ft|m}} above sea-level at {{convert|45|nmi|km}},{{sfnp|Woodward|Robinson|1992|page=10 }}{{sfnp|Middlebrook|2012|page=156 }} though it was the UAA1 radar warning receiver that drew attention to the contacts.{{sfnp|Woodward|Robinson|1992|page=10 }}{{efn|name=UAA1|Woodward's book ''One Hundred Days'' (page 10) says that the initial detection was on the "UAA 1 console".{{sfnp|Woodward|Robinson|1992|page=10 }} Hampshire's book ''British Guided Missile Destroyers'' (page 13) explains that Type 42 destroyers were equipped with "UAA1 (Abbey Hill)" from 1978, and says that this is a type of electronic warfare equipment it calls "intercepts", which "detect and identify the radars of approaching aircraft, ships and missiles."{{sfnp|Hampshire|2016|page=13}} }}

The Type 965 radars used radio frequencies that were used by television stations, and therefore caused interference with television (and vice versa) if used near land in Europe.<ref name=Innovation256/> Type 965 was superseded by the Type 1022 radar, which did not have this disadvantage.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

== Adoption == During 1954-55, reports on most fleet exercises showed that there was an urgent need for radar picket ships. These would require a suitable radar. The need for such a radar had been raised as a staff requirement in May 1950. In 1955, four radars were considered:{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}<ref name=Innovation256 >{{harvnb|Friedman, Innovation and Defence|pages=255–256 }}</ref> *The American AN/SPS-6C radar, which was credited with a range of {{convert|50|nmi|km}} at {{convert|15,000|ft|m}}, and {{convert|90|nmi|km}} at {{convert|60,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *The Dutch LW-02 radar, which was credited with a range of {{convert|75|nmi|km}} at {{convert|35,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *A Marconi's Wireless Telegraph Company commercial design originally conceived for land-based air defence,<ref name=Innovation256 /> which was credited with a range of {{convert|70|nmi|km}} at {{convert|35,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Extending the range of the Type 992 radar, by slowing its scanning rate.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

A potential route for the Royal Navy to get the SPS-6C was the Mutual Defense Assistance program (MDAP), but by 1954-5 the programme was running down.<ref name=Innovation256/> In addition, it was thought that getting spares for the SPS-6C radar could be a problem, because the United States Navy considered it obsolescent.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} The Marconi design was chosen and was named Type 965.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} The Type 965M was introduced in about 1960, and used the original AKE(1) aerial with an improved receiver and feeder.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

== Ships with Type 965 radars == [[File:Bacchante from Targatness June73 proc.jpeg|HMS ''Bacchante'' in June 1973, with the Type 965M radar's single bedstead AKE(1) aerial on her mainmast.|thumb|right]] [[File:HMS Lincoln. 1972.jpg|HMS ''Lincoln'' in 1972, with the Type 965P radar's double bedstead AKE(2) aerial on her mainmast.|thumb|right]] *Type 965M with AKE(1) aerial **The aircraft carrier HMS ''Ark Royal'' was given a Type 965M system on her foremast when modernised in 1958-59.{{sfn|Marriott, Royal Navy Aircraft Carriers|page=65 }} **Type 41 ''Leopard''-class frigates when modernised.{{sfnp|Jane's|1975|page=360}} **Type 81 Tribal-class frigates.{{sfnp|Jane's|1975|page=359}} **Type 12I ''Leander''-class frigates (though removed in the eight ships given the Ikara conversion in 1970-78 and the five ships given the Seawolf missile conversion in 1978-84).{{sfn|Marriott, Royal Navy Frigates|pages=87,94 }} **Weapon-class destroyers modernised to air direction destroyers. **County-class destroyers Batch 1.{{sfn|Marriott, Royal Navy Destroyers|page=105 }} **The aircraft carrier HMS ''Centaur'' when refitted in 1963. The radar was taken from the air direction destroyer ''Battleaxe''. **''Tiger''-class cruisers when modernised in the late 1960s. **The carrier HMS ''Hermes'' when converted from the aircraft carrier role to the commando carrier role in 1971-73.{{sfn|Marriott, Royal Navy Aircraft Carriers|page=96 }}{{sfnp|Dyson|1984|page=85}} *Type 965P with AKE(2) aerial **Battle-class destroyers - the four that were modernised to air direction destroyers. **Type 61 ''Salisbury''-class frigates when modernised in 1961-68.{{sfnp|Friedman, British Destroyers & Frigates|page=203}}{{sfnp|Jane's|1966|page=296}} HMS ''Chichester'' had her Type 965 removed in 1973 when she was refitted as Hong Kong guardship.{{sfnp|Jane's|1975|page=361}} **County-class destroyer Batch 2.{{sfn|Marriott, Royal Navy Destroyers|page=105 }}{{sfnp|Jane's|1982|page=551}} **The aircraft carrier HMS ''Eagle'' was given a Type 965Q on her lattice foremast when modernised in 1959-64.{{sfn|Marriott, Royal Navy Aircraft Carriers|page=61 }} **Type 82 destroyer, the sole ship HMS ''Bristol'' described as "Type 965 with double AKE array and IFF". {{sfnp|Jane's|1982|page=551}} before it was replaced by Type 1022 radar when she was modernised in 1984-6.{{sfn|Marriott, Royal Navy Destroyers|page=115 }} *Type 965Q with AKE(1) aerial *Type 965R with AKE(2) aerial **The aircraft carrier HMS ''Ark Royal'' was given two Type 965R systems on separate masts when modernised in 1967-70.{{sfnp|Jane's|1975|page=347}}{{sfn|Marriott, Royal Navy Aircraft Carriers|page=68 }} **Type 42 destroyer Batch 1; Batch 2 had the Type 1022.{{sfnp|Jane's|1982|page=553}}{{sfn|Marriott, Royal Navy Frigates|page=118 }}

== Technical specifications == A common aerial was used for transmitting and receiving.<ref name=BR_333(1)/> This was the single bedstead AKE(1) in the Type 965M, and the double bedstead AKE(2) in the Type 965P.<ref name=BR_333(1)/> The 965M and 965P were integrated with IFF Mk 10.<ref name=BR_333(1)/> The radar displayed both to an "office display unit" (monitor unit design 44), and up to six remote plan position indicator (PPI) displays.<ref name=BR_333(1)/>

{| class="wikitable" |-valign=top |- |+Type 965M and 965P specifications |- ! !Type 965M and 965P <ref name=BR_333(1) >{{cite web |url=http://marconiradarhistory.pbworks.com/f/53951375/965M%20AND%20P%20AE%20AKE%5B2%5D.pdf |title=Type 965M/P Summary of Data, BR 333(1) |website=marconiradarhistory.pbworks.com|access-date=2 June 2017 }}</ref><ref >{{cite web |url=http://www.rnmuseumradarandcommunications2006.org.uk/Radar/pdfs/965m.pdf |title=Type 965M/P Summary of Data, BR 333(1) |website= HMS Collingwood Heritage Collection |access-date=17 June 2018 }}</ref><ref name=CountyRadar >{{cite web |url=http://www.littlewars.org.uk/radar.html |title=Radar sets of the County Class|date=14 January 2014 |first1=SR |last1=Jenkins|website=www.littlewars.org.uk|access-date=2 June 2017 }}</ref> ! Type 965Q and 965R <ref name=965QR >{{cite web |url=http://www.rnmuseumradarandcommunications2006.org.uk/Radar/pdfs/965q.pdf |title=Type 965Q/R Summary of Data, BR 333(1) |website= HMS Collingwood Heritage Collection |access-date=17 June 2018 }}</ref> |- | Frequency | colspan=2 align=center | 216-224 MHz |- | Wavelength | colspan=2 align=center | approximately {{convert|1.4| m|ftin|abbr=on}} |- | Power output | colspan=2 align=center | 450 kW |-valign=top || Pulse repetition frequency (PRF) || 200 or 400 pulses per second (p/s) nominal || See below |-valign=top || Pulse width || 3.8 μs (with 400 p/s PRF) <br>10 μs (with 200 p/s PRF) ||4 μs (nominal for MTI working) <br>10 μs (for non-MTI working) |-valign=top | Aerial rotation speed | colspan=2 align=center | 10 revolutions per minute |-valign=top | Intermediate frequency | colspan=2 align=center | 13.5 MHz |-valign=top | Aerial beam width | colspan=2 align=center | 12° (horizontal), 40° (vertical) |-valign=top || Receiver bandwidth || long pulse 120 kHz, short pulse 330 kHz ||long pulse 120 kHz, short pulse (MTI) 330 kHz |}

;Differences between Type 960 and 965M *Type 965 receiver noise factor: 8 dB.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Type 965M receiver noise factor: 4.5 dB.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Type 965M feeder was 1 dB better than the Type 960 feeder.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

; Range *Type 960: credited during appraisal as {{convert|70|nmi|km}} at {{convert|35,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Type 960: {{convert|120|nmi|km}} against an English Electric Canberra at {{convert|20,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Type 965M: {{convert|200|nmi|km}} at {{convert|45,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }} *Type 965P: {{convert|280|nmi|km}} at {{convert|100,000|ft|m}}.{{sfn|Friedman, British Destroyers & Frigates|pages=162, 176 }}

=== Type 965Q and 965R === The receiver of the Type 965Q and 965R used "a coherent oscillator (COHO) to provide the coherence in phase between transmission and reception. The COHO is phase locked to the transmitter pulse."<ref name=965QR/> With the Type 965Q and 965R, the pulse repetition frequency (PRF) had a number of different settings.<ref name=965QR/> *In non-MTI mode, the PRF was set by the Pulse Synchronising Outfit RSE.<ref name=965QR/> *In MTI mode, to avoid interference from other radars, there were five available pulse intervals, each with a corresponding stagger time. Pulse intervals were ±3 μs; stagger times were ±2 μs.<ref name=965QR/> **2580 μs pulse interval ±516 μs stagger time **2590 μs pulse interval ±518 μs stagger time **2600 μs pulse interval ±520 μs stagger time **2610 μs pulse interval ±522 μs stagger time **2620 μs pulse interval ±524 μs stagger time

== Notes == {{notelist}}

== References == {{Reflist}}

==Publications== {{Commonscat|Type 965 radar}} *{{cite book |title=HMS Hermes 1959-1984 |last1=Dyson |first1=Tony |publisher=Maritime Books |year=1984 |isbn=0-907771-16-5 }} *{{cite book |first1=Norman |last1=Friedman |authorlink=Norman Friedman |title=British Destroyers & Frigates, the Second World War and After |edition=2 |publisher=Seaforth Publishing |year=2008 |isbn=978-1848320154 |ref={{harvid|Friedman, British Destroyers & Frigates}} }} *{{cite book |first1=Norman |last1=Friedman |title=British Cruisers, Two World Wars and After |publisher=Seaforth Publishing |year=2012 |isbn=978-1848320789 |ref={{harvid|Friedman, British Cruisers}} }} *{{cite book |title=The Royal Navy, 1930-2000: Innovation and Defence |editor-first1=Richard|editor-last1=Harding |first1=Norman|last1=Friedman |publisher=Frank Cass |year=2005 |isbn= 9780714657103 |ref={{harvid|Friedman, Innovation and Defence}} }} *{{citation|title=British Guided Missile Destroyers: County-class, Type 82, Type 42 and Type 45|first1=Edward|last1=Hampshire|publisher=New Vanguard, Bloomsbury Publishing|date=2016|isbn=9781472811172}} *{{citation |url=http://www.littlewars.org.uk/radar.html |title=Radar sets of the County Class|date=14 January 2014 |first1=SR |last1=Jenkins |website=www.littlewars.org.uk |access-date=2 June 2017 }} *{{citation |title=Royal Navy Frigates Since 1945 |first1=Leo |last1=Marriott |edition=2 |publisher=Ian Allan Ltd |year=1990 |isbn=0-7110-1915-0 |ref={{harvid|Marriott, Royal Navy Frigates}} }} *{{citation |title = Royal Navy Destroyers Since 1945 |first1 = Leo |last1 = Marriott |publisher = Ian Allan |year = 1989 |isbn = 0-7110-1817-0 |ref = {{harvid|Marriott, Royal Navy Destroyers}} |url-access = registration |url = https://archive.org/details/royalnavydestroy0000marr }} *{{citation|title=Royal Navy Aircraft Carriers 1945-1990 |first1=Leo|last1=Marriott |year=1985 |isbn=0-7110-1561-9 |ref={{harvid|Marriott, Royal Navy Aircraft Carriers}} }} *{{cite book |title=The Falklands War |first1=Martin|last1=Middlebrook|isbn=978-1848846364|publisher=Pen & Sword Military |year=2012 |edition=4 }} *{{cite book |title=Wings of the Malvinas: The Argentine Air War Over the Falklands |first1=Santiago |last1=Rivas |edition=reprint |year=2012 |isbn=978-1902109220 |publisher=Hikoki Publications }} *{{cite book |title=One Hundred Days: The Memoirs of the Falklands Battle Group Commander |first1=Sandy |last1=Woodward |authorlink=Sandy Woodward |first2=Patrick|last2=Robinson |publisher=Naval Institute Press |year=1992|isbn=1-55750-651-5 }} *{{cite book |title=Jane's Fighting Ships 1966-67 |editor-first=Raymond V B|editor-last=Blackman |year=1966 |publisher=Sampson Low, Marston & Co |ref={{harvid|Jane's|1966}} }} *{{cite book |title=Jane's Fighting Ships 1975-76|editor-first=John E|editor-last=Moore |year=1975|isbn=0-354-00519-7|publisher=Macdonald and Jane's |ref={{harvid|Jane's|1975}} }} *{{cite book |editor-first=John|editor-last=Moore |title=Jane's Fighting Ships 1982-83 |url=https://archive.org/details/janesfightingshi00publ|url-access=registration|year=1982 |publisher=Jane's Publishing Company |isbn=0-7106-0742-3 |ref={{harvid|Jane's|1982}} }} *{{citation|url=http://www.rnmuseumradarandcommunications2006.org.uk/960.pdf|title=Type 960 Summary of Data, BR 333(1)|website=www.rnmuseumradarandcommunications2006.org.uk|access-date=3 June 2017}} *{{citation|url=http://marconiradarhistory.pbworks.com/f/53951375/965M%20AND%20P%20AE%20AKE%5B2%5D.pdf |title=Type 965M/P Summary of Data, BR 333(1)|website=marconiradarhistory.pbworks.com|access-date=2 June 2017}} *{{citation|url=http://www.rnmuseumradarandcommunications2006.org.uk/965M%20AND%20P%20AE%20AKE[2].pdf|title=Type 965M/P Summary of Data, BR 333(1)|website=www.rnmuseumradarandcommunications2006.org.uk|access-date=2 June 2017}} *{{citation|url=http://www.rnmuseumradarandcommunications2006.org.uk/965%20Q%20AND%20R.pdf|title=Type 965Q/R Summary of Data, BR 333(1)|website=www.rnmuseumradarandcommunications2006.org.uk|access-date=2 June 2017}}

Category:Naval radars Category:Royal Navy Radar