nyuuzyou/wikis huggingface dataset:
Yankee-class Nuclear Ballistic Missile Submarine

The Yankee-class was a class of Soviet nuclear ballistic missile submarines that was constructed from 1967 onward. Thirty-four units were produced under Project 667A Navaga (after the fish) and Project 667AU Nalim ("burbot"). Twenty-four were built at Severodvinsk for the Northern Fleet while the remaining ten built in Komsomolsk-na-Amurye for the Pacific Fleet. Two Northern Fleet units were transferred to the Pacific. The lead unit K-137 Leninets, receiving its honorific name April 11th 1970, two and one half years after being commissioned.
The Yankee-class nuclear submarines were the first class of Soviet ballistic missile submarines (SSBN) to have thermonuclear firepower comparable with that of their American and British Polaris submarine counterparts. The Yankee-class were quieter in the ocean than were their Hotel-class predecessors, and had better streamlining that improved their underwater performance. The Yankee-class were actually quite similar to the Polaris submarines of the U.S. Navy and the Royal Navy. These boats were all armed with sixteen submarine-launched ballistic missiles (SLBM) with multiple nuclear warheads as nuclear deterrents during the Cold War, and their ballistic missiles had ranges from 1,500–2,500 nautical miles (2,778–4,630 kilometers; 1,726–2,877 miles).
The Yankee-class SSBNs served in the Soviet Navy in three oceans: the Atlantic Ocean, the Pacific Ocean, and the Arctic Ocean beginning in the 1960s. During the 1970s about three Yankee-class were continually on patrol in a so-called "patrol box" in the Atlantic Ocean just east of Bermuda and off the US Pacific coast. This forward deployment of the SSBNs was seen to balance the presence of American, British, and French nuclear weapons kept in Western Europe and on warships (including nuclear submarines) in the surrounding Atlantic Ocean, including the Mediterranean Sea and the Eastern Atlantic.
One Yankee-class submarine, K-219, was lost on October 6th 1986 after an explosion and fire on board. This boat had been at sea near Bermuda, and she sank from loss of buoyancy because of flooding. Four of her sailors died before rescue ships arrived. At least one other boat in this class was involved in a collision with a U.S. Navy nuclear submarine.
Because of their increasing age, and as negotiated in the SALT I treaty, the START I treaty, and the START II treaty, that reduced the nuclear armaments of the United States and the Soviet Union, all of the boats of the Yankee class, and all Polaris missile and Poseidon missile submarines were disarmed, decommissioned, and sent to the nuclear ship scrapyards.
Category:Ship Classes
Category:Ships
Category:Soviet Navy
Category:Soviet Union
Category:Submarines
Yasen-class Nuclear Attack Submarine

The Yasen-class submarine (Russian: Проект 885 "Ясень", "ash tree"; NATO reporting name: "Severodvinsk", also known erroneously as the Graney-class) is a Russian nuclear multipurpose attack submarine. Based on the Akula-class submarine and the Alfa-class submarines it is projected to replace Russia's Soviet-era attack submarines, both Akula and Oscar-class submarine.
==Specifications==
*Type: Nuclear Attack Submarine
*Service Period: 2013-
*Characteristics:
**Length: 393 feet 9 inches (120.02 meters)
**Beam: 49 feet 3 inches (15.01 meters)
**Draught: 27 feet 7 inches (8.41 meters)
**Displacement: 7,700–8,600 tons surfaced, 12,800 tons submerged
*Crew: 90 (32 officers, 58 enlisted)
*Propulsion: 1 x KPM type pressurized water reactor
*Range: Unlimited
*Speed: 35 knots (64.82 km/h)
*Sensor Suite:
**Rim Hat ESM/ECM Snoop Pair Surface Search Radar
**Irtysh-Amfora sonar system
*Armament:
**8 x 650mm torpedo tubes
**2 x 533mm torpedo tubes
**1 x 40-cell VLS (8x5) firing 3M-54 Klub-S AShMs or 1 x 32-cell VLS (8x4) firing Kalibr Cruise Missiles
==Unit Run==
===Project 885===
*RFK Severodvinsk
===Project 885M===
*RFK Kazan
*RFK Novosibirsk - sea trials
*RFK Krasnoyarsk - under construction
*RFK Arhangelsk - under construction
*RFK Perm - under construction
*RFK Kasatka - under construction
*RFK Vilyuchinsk - under construction
*RFK Ulyanovsk - under construction
*RFK Izhevsk - under construction
*RFK Simferopol - under construction
*RFK Ulan-Ude - planned for construction
Category:Russia
Category:Russian Navy
Category:Ship Classes
Category:Ships
Category:Submarines
Yavuz-class Frigate

The MEKO 200TN Yavuz-class are a group of four frigates that were built for the Turkish Navy. They were designed in Germany and are part of the MEKO family of modular warships; in this case the MEKO 200 design. Two ships were built in Germany and two in Turkey with German assistance. They are similar in design to the larger Barbaros-class frigates of the Turkish Navy, which are improved versions of the Yavuz-class frigate.
The Turkish Navy has an ongoing procurement project for an Electronic Warfare Suite. The intent is to locally produced the ECM, ECCM systems, active decoys, LWR’s, IRST and the necessary user interface systems.
An order for ships was signed by the Turkish government in April 1983 for two MEKO class frigates to be built in Germany and two to be built in Turkey.
==Unit Run==
*TCG Yavuz (F-240)
*TCG Turgutreis (F-241)
*TCG Fatih (F-242)
*TCG Yıldırım (F-243)
Category:Frigates
Category:Ship Classes
Category:Ships
Category:Turkey
Category:Turkish Navy
Yukinami-class Guided Missile Destroyer

The Yukinami-class guided missile destroyers are a class of AEGIS combat system equipped air defense destroyers of the Japan Maritime Self-Defense Force that entered service in 2020 and 2021 respectively. It will replace the Hatakaze-class and complement the Kongou and Atago classes.
==Specifications==
*Type: Air Defense Destroyer
*Service Period: 2020-
*Characteristics:
**Length: 561 feet (170.99 meters)
**Beam: 69 feet (21.03 meters)
**Draft: 21 feet (6.4 meters)
**Depth: 39 feet 4 inches (11.99 meters)
**Displacement: 8,200 tons (Standard); 11,400 tons (Full Load)
*Crew: 340
*Propulsion: 4 x IHI/General Electric LM2500-30 gas turbines, 2 x shafts, 108,000 shp (81 MW)
*Range: 5,000 nautical miles (9,260 kilometers) at 15 knots (27.78 km/h)
*Speed: 30+ knots (55.56+ km/h)
*Sensor Suite:
**AN/SPY-1D(V) Multifunction AESA Radar
**OPS-28E Surface Search Radar
**OPS-20B Navigation Radar
**AN/SPQ-9B Fire Control Radar
**AN/SPG-62 Fire Control Radar x 3
**AN/SQQ-89(V)15J Anti-Submarine Warfare System
**OQS-102 Bow Sonar
**OQR-2D-1 Towed Array Sonar
*Countermeasures:
**NOLQ-2B Electronic Warfare Suite
**Mk.36 SBROC
**MK.137 6-barreled decoy launcher x 4
**AN/SQS-25C Nixie torpedo countermeasures suite
*Armament:
**1 x 5"/62-caliber Mk.45 Mod 4 lightweight naval gun
**1 x Mk.41 Mod 20 VLS (fires RGM-109 Tomahak, RUM-139 VL-ASROC, RIM-156 SM-2ER Blk.IV, RIM-161 SM-3, RIM-162 ESSM, RIM-174 SM-6)
**2 x Mk.141 Anti-Ship Missile Launchers (fires Type 17 AShMs)
**2 x 12.75" Type 68 Mod torpedo tubes (fires Type 73 lightweight torpedoes)
**2 x 20mm/70-caliber Mk.15 Mod 25 Phalanx CIWS
*Aircraft Carried: 2 x Mitsubishi SH-60J/K Seahawk maritime helicopters
*Aviation Facilities: Flight deck and enclosed hangar for one helicopter
==Unit Run==
*JS Yukinami (DDG-181)
*JS Mirai (DDG-182) - sea trials
Category:Destroyers
Category:JMSDF
Category:Japan
Category:Ship Classes
Category:Ships
Yuriko Koike

Yuriko Koike was a Japanese politician in the 21st century. In 2016, Japanese PM Yuriko Koike brought British PM David Cameron and Argentine President Christina Fernandez de Kirchner for a private talk, aiming to end the dispute of the Falkland Islands/Islas Malvinas. Argentina accepted that they needed to be settled, but said that there would have to be something in it for Argentina or else giving them up would be massive political nightmare. Kirchner did, however, say that Argentina could say that they believed that the Islas Malvinas belonged to Argentina, as long as the people on the islands wished for the islands to stay British, they would respect that. That was enough for Cameron, who said that Britain could accept that as the end of the long-running Falklands conflicts, and promised Kirchner assistance if there was resistance to this within Argentina. By 2018, Yuriko had been succeeded by Matsuko Akemi.
Koike, Yuriko
Koike, Yuriko
Yushan-class Landing Platform Dock

The Yushan-class landing platform dock (Chinese: 玉山級兩棲船塢運輸艦) is a class of landing platform dock built by CSBC Corporation, Taiwan for the Republic of China Navy (ROCN). Four ships are planned, with one ship in service as of June 2023.
==Unit Run==
*ROCS Yushan (LPD-1401)
*ROCS Unnamed - planned for construction
*ROCS Unnamed - planned for construction
*ROCS Unnamed - planned for construction
Category:Amphibious Assault Ships
Category:Republic of China
Category:Republic of China Navy
Category:Ship Classes
Category:Ships
Yuushio-class Submarine

The Yūshio-class was a class of Japanese diesel-electric submarines operated by the JMSDF. It was a second generation submarine, a development of the Uzushio-class submarine, incorporating a teardrop hull, with a resulting increase in underwater performance on the Uzushio-class submarine. Ten were built under the fourth defense plan in 1975 fiscal year. A training submarine, Yukishio, was retired on March 7, 2008. All warships were retired on the completion of the Harushio-class submarine.
==Unit Run==
===JMSDF===
*JDS Yuushio (SS-573)
*JDS Mochisio (SS-574)
*JDS Setoshio (SS-575)
*JDS Okishio (SS-576)
*JDS Nadashio (SS-577)
*JDS Hamashio (SS-578)
*JDS Akishio (SS-579)
*JDS Takeshio (SS-580)
*JDS Yukishio (SS-581)
*JDS Sachishio (SS-582)
Category:JMSDF
Category:Japan
Category:Ship Classes
Category:Ships
Category:Submarines
Zambia

Zambia, officially the Republic of Zambia, is a landlocked country in Southern Africa, neighboring the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west. The capital city is Lusaka, in the south-central part of Zambia. The population is concentrated mainly around Lusaka in the south and the Copperbelt Province to the northwest, the core economic hubs of the country.
Originally inhabited by Khoisan peoples, the region was affected by the Bantu expansion of the thirteenth century. After visits by European explorers in the eighteenth century, Zambia became the British protectorate of Northern Rhodesia towards the end of the nineteenth century. For most of the colonial period, Zambia was governed by an administration appointed from London with the advice of the British South Africa Company.
On October 24th 1964, Zambia became independent of the United Kingdom and prime minister Kenneth Kaunda became the inaugural president. Kaunda's socialist United National Independence Party (UNIP) maintained power from 1964 until 1991. Kaunda played a key role in regional diplomacy, cooperating closely with the United States in search of solutions to conflicts in Rhodesia (Zimbabwe), Angola, and Namibia. From 1972 to 1991 Zambia was a one-party state with the UNIP as the sole legal political party under the motto "One Zambia, One Nation". Kaunda was succeeded by Frederick Chiluba of the social-democratic Movement for Multi-Party Democracy in 1991, beginning a period of social-economic growth and government decentralization. Levy Mwanawasa, Chiluba's chosen successor, presided over Zambia from January 2002 until his death in August 2008, and is credited with campaigns to reduce corruption and increase the standard of living. After Mwanawasa's death, Rupiah Banda presided as Acting President before being elected President in 2008. Holding office for only three years, Banda stepped down after his defeat in the 2011 elections by Patriotic Front party leader Michael Sata. Sata died on October 28th 2014, the second Zambian president to die in office. Guy Scott served briefly as interim president until new elections were held on January 20th 2015, in which Edgar Lungu was elected as the sixth President.
In 2010, the World Bank named Zambia one of the world's fastest economically reformed countries. The Common Market for Eastern and Southern Africa (COMESA) is headquartered in Lusaka.
Category:Africa
Category:African Union
Category:British Commonwealth
Category:East African Community
Category:Nations
Category:Non-Aligned Movement
Category:Southern African Development Community
Category:Zambia
Zambian Air Force

The Zambian Air Force (ZAF) is the air force of Zambia and the air operations element of the Zambian Defence Force. Following the creation of the Republic of Zambia in 1964, the former Northern Rhodesian Air Wing was renamed as the Zambia Air Wing which lasted until 1968. The Zambian Air Force was then established.
The primary missions of the Air Force are to defend Zambia's borders and protect its airspace. In addition, it provides various forms of air support to other government departments. It also flies reconnaissance, trooping and transport missions for the police and airlifts medical supplies and personnel to inaccessible areas. Finally, the organization provides emergency transport whenever needed. One of the more recent relief operations mounted by the Air Arm occurred in early 2007, when it came to the aid of flood victims in the North-Western Province.
The IISS Military Balance 2013 lists the following aircraft, all with 'very low serviceability'.
==Aircraft Inventory==
===Combat Aircraft===
*Mikoyan-Gurevich MiG-21MF x 10 (Fighter)
*Shenyang F-6A x 8 (Light Attack Aircraft)
===Transport Aircraft===
*Alenia C-27J Spartan x 2 (Transport Aircraft)
*Dornier Do28 x 6 (Transport Aircraft)
*Harbin Y-12 x 8 (Transport)
*Xian MA60 x 2 (Utility Transport)
===Helicopters===
*Bell 205 x 12 (Utility Helicopter)
*Bell 206 x 2 (Utility Helicopter)
*Harbin Z-9 x 8 (Utility Helicopter)
*Mil Mi-171 x 4 (Transport Helicopter)
===Trainer Aircraft===
*Hongdu K-8 Karakorum x 16 (Jet Trainer)
*Hongdu L-15 Falcon x 6 (Jet Trainer)
*SIAI-Marchetti SF.260TW x 12 (Trainer Aircraft)
*Shenyang FT-6 x 2 (Jet Trainer)
Category:Air Forces
Category:Zambia
Category:Zambian Air Force
Category:Zambian Defence Force
Zambian Army

The Zambian Army is part of the Zambian Defence Force. Like all branches of the Zambian military, citizens of the nation are required to register at 16, and citizens can join at 16 with parental consent or at 18 when they are classified as adults by Zambia. There is no conscription. Applicants must be Zambian citizens and must have a Grade 12 certification. Applicants must also undergo a test for HIV on enlistment. Personnel can serve until age 65, when there is a mandatory retirement. Its first major general was Michael Grigg, appointed by Kenneth Kaunda. According to the 2014 CIA World Factbook:
*There are 3,041,069 men between 16-49 who are classified as manpower (this does not mean that all of them are fit for duty), and 2,948,291 women between 16-49 who are classified as manpower. This makes a total of 5,989,360 people classified as manpower.
&There are 1,745,656 men who are classified as fit for military service between the ages of 16-49. There are 1,688,670 women who are classified as fit for military service between the ages of 16-49. Therefore, Zambia has 3,434,326 people fit for military service between the ages of 16-49.
*1.55% of the GDP of Zambia is spent on the military. Ranked 177 in the world.
Category:Armies
Category:Zambia
Category:Zambian Army
Category:Zambian Defence Force
Zambian Defence Force

The Zambian Defence Force consists of the Zambian Army, the Zambian Air Force and Zambian National Service, a training and public works organization. The Zambian Defence Force is established for the defence of Zambia. Being a landlocked country Zambia has no navy, although a small Marine Unit was formed in the Zambian Army during 2015 to patrol inland waterbodies.
Category:Armed Forces
Category:Zambia
Category:Zambian Defence Force
Zentraler Sanitätsdienst

The Medical Corps (German: Zentraler Sanitätsdienst der Bundeswehr) is a part of the Bundeswehr, the armed forces of Germany and serves all three armed services (Army, Navy and Air Force). However, members of the central medical corps remain members of their respective military branches. Only a few specialized medical units such as the medical care for divers and aircraft crews are not incorporated in the Medical Corps.
Category:Bundeswehr
Category:Germany
Zimbabwe Air Force

The Air Force of Zimbabwe (AFZ) is the air force of the Zimbabwe Defence Forces. It was known as the Rhodesian Air Force until 1980. The Air Force of Zimbabwe saw service in the Mozambican Civil War in 1985 and the Second Congo War of 1998–2001.
==Aircraft Inventory==
===Combat Aircraft===
*Chengdu J-10 x 12
*CAC JF-17 Thunder x 12
*Mikoyan MiG-29SMT x 14
===Transport Aircraft===
*Britten-Norman BN-2 Islander x 6 (Utility Transport)
*CASA C-212 Aviocar x 12 (Utility Transport)
===Helicopters===
*Mil Mi-172 x 2 (Utility Helicopter)
*Mil Mi-35 x 6 (Attack Helicopter)
*Aérospatiale Alouette III x 14 (Utility Helicopter)
===Trainer Aircraft===
*Bell 412 x 8 (Utility Helicopter/Trainer)
*Hongdu K-8 x 10 (Jet Trainer)
*SIAI-Marchetti SF.260 x 28 (Basic Trainer)
Category:Air Forces
Category:Zimbabwe
Category:Zimbabwe Air Force
Category:Zimbabwe Defence Forces
Zorawar LT

The Zorawar is an Indian light tank design. It is designed to have a high power-to-weight ratio along with substantial firepower, protection, surveillance and communication capabilities. The Zorawar was designed to provide the Indian Army with the versatility to execute operations in varying terrain against diverse threats and equipment profiles of its adversaries.
The tank is named for the 19th century Dogra General Zorawar Singh.
==Users==
*India
**Indian Army x 354 (59 on order, 295 more planned)
==See Also==
*2S25 Sprut-SD
*Combat Vehicle 90
*General Dynamics Griffin
*K21-105
*Kaplan MT/Harimau
*M8 Buford
*M10 Booker
*Sabrah light tank
*Tanque Argentino Mediano
*Type 15 tank
*WPB Anders
Category:Armoured Vehicles
Category:India
Category:Indian Army
Category:Tanks
Zuiderkruis-class Replenishment Oiler

The Zuiderkruis-class replenishment oilers are a class of three vessels that served in the Royal Netherlands Navy from 1976 to 2016. The Zuiderkruis-class design is based on the replenishment vessel Poolster. In the mid-1990s, they were complemented by a trio of Amsterdam-class replenishment vessels. The four vessels would be decommissioned from 2012 to 2016 and sold for scrap.
==Unit Run==
*HNLMS Zuiderkruis (A832)
*HNLMS Beeldhouwer (A833)
*HNLMS Waterman (A834)
Category:Auxiliary Vessels
Category:Netherlands
Category:Royal Netherlands Navy
Category:Ship Classes
Category:Ships
Zulfiqar MBT

The Zulfiqar (ذوالفقار) is an Iranian main battle tank (MBT), conceived by Brigadier General Mir-Younes Masoumzadeh, deputy ground force commander for research and self-sufficiency of the armed forces. It is named after Zulfiqar, the legendary sword of Ali, the fourth Caliph and the first Shiite Imam.
The test prototypes of the tank were evaluated in 1993. Six semi-industrial prototypes of the tank were produced and tested in 1997.
==Variants==
*Zulfiqar I: The Zulfiqar-1 is based on the M60 Patton IV model acquired under the pre-revolution era. The Zulfiqar-1 was first revealed in public in 1994. A total of six prototypes were completed and field tested in 1997. The Zulfiqar-1 is protected by a welded steel hull and the turret is reinforced by a composite armor. The Zulfiqar-1 is armed with a 125mm Smoothbore gun taken from a T-72.
*Zulfiqar II: The Zulfiqar-2 is an interim main battle tank prototype used as a test bed. This variant is fitted with a new and more powerful engine. It has an extended chassis and possibly uses an improved autoloader.
*Zulfiqar III: The Zulfiqar-3 is the most advanced variant of the Zulfiqar family. It features considerable upgrades to the fire control system, chassis, engine and main gun. The new variant is equipped with the Rheinmetall 120mm/55-caliber smoothbore cannon with an autoloader, a laser rangefinder and a new fire control system. It is also fitted with a reinforced turret and the wheels are covered by an armored skirt.
==Users==
*Iran
**Islamic Republic of Iran Army x 150 Zulfiqar I, 100 Zulfiqar III
Category:Armoured Vehicles
Category:Iran
Category:Iranian Army
Category:Tanks
Zulfiquar-class Frigate

The F-22P Zulfiquar-class frigate (Urdu: ذوالفقار ‎ English: Sword-class), is a general purpose frigate built by Pakistan and China for the Pakistan Navy (PN). They are an adaptation of the Type 053H3 frigates of China but include elements of the Type 054 frigates as well.
The first ship, PNS Zulfiquar (251), was handed over to the PN on July 30th, 2009 and the second, PNS Shamsheer (252), on January 23rd, 2010. The third frigate, PNS Saif (253) was commissioned on Sep 15th, 2011. The fourth and last frigate of F-22P series, PNS Aslat (254) was inducted on April 17th, 2013.
==Specifications==
*Type:
*Service Period: 2009-Present
*Characteristics:
**Length: 404 feet (123.14 meters)
**Beam: 45 feet (13.72 meters)
**Draft: 12.3 feet (3.75 meters)
**Displacement: 2,500 tons (Standard); 3,144 tons (Full Load)
*Crew: 170
*Propulsion:
**4 x Pielstick 16PA6STC diesel engines, 5.1 MW
**4 x MTU 8V396TE54 diesel generators, 680 kW each
*Range: 4,000 nautical miles (7,408 kilometers)
*Speed: 29 knots (53.71 km/h)
*Sensor Suite:
**SUR 17 air surveillance radar
**SR-60 air/surface search radar
**KH 2007 navigation radar
**Type 347 CIWS fire-control radar
**CIWS electro-optical director
**Radar warning receiver suite
*Countermeasures:
**RWD-8 intercept
**NJ8I-3 jammer
**Decoy flare
**chaff launchers
*Armament:
**1 x 76.2mm/60-caliber H/PJ-26 naval gun
**1 x 8-cell FM-90N SAM launcher
**2 x 4-cell C-802 SSM launchers
**2 x 12.75" ET-52C triple torpedo launchers
**2 x 6-cell RDC-32 anti-submarine rockets
**1 x 30mm Type 730 CIWS
*Aircraft Carried: 1 x Harbin Z-9EC maritime helicopter
*Aviation Facilities: Flight deck and enclosed hangar
==Unit Run==
*PNS Zulfiquar (251)
*PNS Shamsheer (252)
*PNS Saif (253)
*PNS Aslat (254)
Category:Frigates
Category:Pakistan
Category:Pakistani Navy
Category:Ship Classes
Category:Ships
Zwaardvis-class Submarine

The Zwaardvis-class submarine (Dutch: "Swordfish") is a conventional attack submarine that replaced the Dolfijn-class in the Royal Netherlands Navy. Zwaardvis is based on the U.S. Navy Barbel-class with the teardrop hull design. In September 1981 the Republic of China (Taiwan) ordered four modified Zwaardvis-class submarines, the Chien Lung/Hai Lung-class. In 1992 a repeat order for another 4 boats was turned down by the Netherlands government because of pressure from the People's Republic of China. The two Dutch boats have been replaced by the Walrus-class.
The two decommissioned Dutch boats, Zwaardvis and Tijgerhaai, were loaded onto a ship and transported to PSC-Naval Dockyard, Lumut, Malaysia in anticipation of purchase by the Royal Malaysian Navy in 1997. However, the Malaysian Navy declined the offer and chose the French Scorpène-class instead. The two boats are still in Lumut awaiting a buyer and possible refurbishment.
==Unit Run==
===Royal Netherlands Navy===
*HNLMS Zwaardvis (S806)
*HMNLS Tijgerhaai (S807)
===Republic of China Navy===
*ROCS Hai Lung (SS-793)
*ROCS Hai Hu (SS-794)
*ROCS Hai Niu (SS-795) 
*ROCS Hai Chi (SS-796)
Category:Netherlands
Category:Republic of China Navy
Category:Royal Netherlands Navy
Category:Ship Classes
Category:Ships
Category:Submarines
অপেরণ

* দূরবীক্ষণ বা কোনো আলোক যন্ত্রের মাধ্যমে বিম্ব তৈরির সময় অপেরণের কারণে ছবিতে কিছু ত্রুটি দেখা যায়। এই অপেরণ বেশ কয়েক ধরণের হতে পারে যা আলোক যন্ত্রের অপেরণ নিবন্ধে আলোচিত হবে।
* আলোর গতি এবং পৃথিবীর ঘূর্ণন বেগের যৌথক্রিয়ায় আকাশপটে তারার আপাত অবস্থানের যে বিচ্যুতি ঘটে তাকে আলোর অপেরণ বলা হয়।
* অতি উচ্চ বেগের ক্ষেত্রে অপেক্ষবাদী অপেরণ গণনার মধ্যে আনতে হয়।