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Sector Clock
A Sector clock or colour change clock was a round colour-coded clock used at military airfields and observation posts in the United Kingdom to help track the movements of enemy aircraft and control friendly aircraft. History Originally known as "colour change clocks", they were introduced during the First World War by the Royal Flying Corps in 1917 to monitor the movements of German aircraft. Later, during the Second World War they played a significant role in the Battle of Britain and continued to be used by the Royal Air Force and Royal Observer Corps (ROC) as simple clocks and keepsakes, until the end of the Cold War period. These clocks are now sought after by collectors of aeronautica. There were two versions of the clock issued, either for RAF Sector use or for the ROC. The RAF Sector Clock has an old style "King's Crown" RAF Warrant Officer's insignia under the "24" at top centre. The ROC clock has a plain face with no insignia. Clocks were either electrical or mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II RAF Sector Clock
In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique while others talk of a "plurality of worlds". Some treat the world as one simple object while others analyze the world as a complex made up of many parts. In ''scientific cosmology'' the world or universe is commonly defined as " e totality of all space and time; all that is, has been, and will be". '' Theories of modality'', on the other hand, talk of possible worlds as complete and consistent ways how things could have been. ''Phenomenology'', starting from the horizon of co-given objects present in the periphery of every experience, defines the world as the biggest horizon or the "horizon of all horizons". In ''philosophy of mind'', the world is commonly contrasted with the mind as that which is represented by the mind. ''Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground-controlled Interception
Ground-controlled interception (GCI) is an air defence tactic whereby one or more radar stations or other observational stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War I by the London Air Defence Area organization, which became the Royal Air Force's Dowding system in World War II, the first national-scale system. The ''Luftwaffe'' introduced similar systems during the war, but most other combatants did not suffer the same threat of air attack and did not develop complex systems like these until the Cold War era. Today the term GCI refers to the style of battle direction, but during WWII it also referred to the radars themselves. Specifically, the term was used to describe a new generation of radars that spun on their vertical axis in order to provide a complete 360 degree view of the sky around the station. Previous systems, notably Chain Home (CH), could only be directed along ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Designs
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the year. Devices operating on several physical processes have been used over the millennia. Some predecessors to the modern clock may be considered as "clocks" that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface. There is a range of duration timers, a well-known example being the hourglass. Water clocks, along with the sundials, are possibly the oldest time-measuring instruments. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1300 in Europe, which kept time with oscillating timekeepers like balance wheels., pp. 103–104., p. 31. Traditionally, in horology, the term ''clock'' was used for a stri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dowding System
The Dowding system was the world's first wide-area ground-controlled interception network, controlling the airspace across the United Kingdom from northern Scotland to the southern coast of England. It used a widespread dedicated land-line telephone network to rapidly collect information from Chain Home (CH) radar stations and the Royal Observer Corps (ROC) in order to build a single image of the entire UK airspace and then direct defensive interceptor aircraft and anti-aircraft artillery against enemy targets. The system was built by the Royal Air Force just before the start of World War II, and proved decisive in the Battle of Britain. The Dowding system was developed after tests demonstrated problems relaying information to the fighters before it was out of date. Air Chief Marshal Hugh Dowding, commander of RAF Fighter Command, solved the problem through the use of hierarchical reporting chains. Information was sent to Fighter Command Headquarters (FCHQ) central ''filter room' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Britain Bunker
The Battle of Britain Bunker is an underground operations room at RAF Uxbridge, formerly used by No. 11 Group Fighter Command during the Second World War. Fighter aircraft operations were controlled from there throughout the War but most notably during the Battle of Britain and on D-Day. Today it is run by Hillingdon Council as a heritage attraction with attached museum. A new visitor centre above ground opened in March 2018. The Bunker is located at RAF Uxbridge, not far from Uxbridge town centre and Uxbridge Underground station. Background As the location of No. 11 Group RAF's Operations Room, The Battle of Britain Bunker was one of the key parts of the world's first integrated air defence system. Often known as the "Dowding system" (after Air Chief Marshal Sir Hugh Dowding, Commander-in-Chief Fighter Command at the time of installation), the system linked Fighter Command with Anti-Aircraft Command, Barrage Balloon Command, the Observer Corps, Chain Home Radio Direction F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordnance Survey National Grid
The Ordnance Survey National Grid reference system (OSGB) (also known as British National Grid (BNG)) is a system of geographic grid references used in Great Britain, distinct from latitude and longitude. The Ordnance Survey (OS) devised the national grid reference system, and it is heavily used in their survey data, and in maps based on those surveys, whether published by the Ordnance Survey or by commercial map producers. Grid references are also commonly quoted in other publications and data sources, such as guide books and government planning documents. A number of different systems exist that can provide grid references for locations within the British Isles: this article describes the system created solely for Great Britain and its outlying islands (including the Isle of Man); the Irish grid reference system was a similar system created by the Ordnance Survey of Ireland and the Ordnance Survey of Northern Ireland for the island of Ireland. The Universal Transverse Merca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
24 Hour Time
The modern 24-hour clock, popularly referred to in the United States as military time, is the convention of timekeeping in which the day runs from midnight to midnight and is divided into 24 hours. This is indicated by the hours (and minutes) passed since midnight, from 0(:00) to 23(:59). This system, as opposed to the 12-hour clock, is the most commonly used time notation in the world today,See the Common Locale Data Repository for detailed data about the preferred date and time notations used across the world, as well the Locale (computer software), locale settings of major computer operating systems, and the article Date and time representation by country. and is used by the international standard ISO 8601.International Standard ISO 8601: Data elements and interchange formats – Information interchange – Representation of dates and times. International Organization for Standardization, 3rd ed., 2004. A number of countries, particularly English-speaking, use the 12-hour clock, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Face
A clock face is the part of an analog clock (or watch) that displays time through the use of a flat dial with reference marks, and revolving pointers turning on concentric shafts at the center, called hands. In its most basic, globally recognized form, the periphery of the dial is numbered 1 through 12 indicating the hours in a 12-hour cycle, and a short hour hand makes two revolutions in a day. A long minute hand makes one revolution every hour. The face may also include a ''second hand'', which makes one revolution per minute. The term is less commonly used for the time display on digital clocks and watches. A second type of clock face is the 24-hour analog dial, widely used in military and other organizations that use 24-hour time. This is similar to the 12-hour dial above, except it has hours numbered 1–24 around the outside, and the hour hand makes only one revolution per day. Some special-purpose clocks, such as timers and sporting event clocks, are designed for mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Digby Ops Room
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allied victory over the Central Powers in 1918, the RAF emerged as the largest air force in the world at the time. Since its formation, the RAF has taken a significant role in British military history. In particular, it played a large part in the Second World War where it fought its most famous campaign, the Battle of Britain. The RAF's mission is to support the objectives of the British Ministry of Defence (MOD), which are to "provide the capabilities needed to ensure the security and defence of the United Kingdom and overseas territories, including against terrorism; to support the Government's foreign policy objectives particularly in promoting international peace and security". The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the year. Devices operating on several physical processes have been used over the millennia. Some predecessors to the modern clock may be considered as "clocks" that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface. There is a range of duration timers, a well-known example being the hourglass. Water clocks, along with the sundials, are possibly the oldest time-measuring instruments. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1300 in Europe, which kept time with oscillating timekeepers like balance wheels., pp. 103–104., p. 31. Traditionally, in horology, the term ''clock'' was used for a stri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army Air Force
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II (1941–1945). It was created on 20 June 1941 as successor to the previous United States Army Air Corps and is the direct predecessor of the United States Air Force, today one of the six armed forces of the United States. The AAF was a component of the United States Army, which on 2 March 1942 was divided functionally by executive order into three autonomous forces: the Army Ground Forces, the United States Army Services of Supply (which in 1943 became the Army Service Forces), and the Army Air Forces. Each of these forces had a commanding general who reported directly to the Army Chief of Staff. The AAF administered all parts of military aviation formerly distributed among the Air Corps, General Headquarters Air Force, and the ground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warrant Officer
Warrant officer (WO) is a rank or category of ranks in the armed forces of many countries. Depending on the country, service, or historical context, warrant officers are sometimes classified as the most junior of the commissioned ranks, the most senior of the non-commissioned officer (NCO) ranks, or in a separate category of their own. Warrant officer ranks are especially prominent in the militaries of Commonwealth nations and the United States. The name of the rank originated in medieval England. It was first used during the 13th century, in the Royal Navy, where Warrant Officers achieved the designation by virtue of their accrued experience or seniority, and technically held the rank by a warrant—rather than by a formal commission (as in the case of a commissioned officer). Nevertheless, WOs in the British services have traditionally been considered and treated as distinct from non-commissioned officers, as such (even though neither group has, technically, held a commiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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