.
Dowding System Made The Battle Of Britain A Success - Forces > .https://youtu.be/bxztuX3fGVM?t=34m22s
resumes: https://youtu.be/bxztuX3fGVM?t=38m3s
resumes: https://youtu.be/bxztuX3fGVM?t=38m3s
ROC & Britain’s Vast Network of Abandoned Nuclear Bunkers | Cold War UK - Calum > .
Aircraft Spotting: How did the Observer Corps help win the Battle of Britain? - iwm > .
Aircraft Spotting: How did the Observer Corps help win the Battle of Britain? - iwm > .
Battle Of Britain: Hugh "Stuffy" Dowding - The Man Who Saved A Nation - War > .
The Royal Observer Corps (ROC) was a civil defence organisation intended for the visual detection, identification, tracking and reporting of aircraft over Great Britain. It operated in the United Kingdom between 29 October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office. Civilian volunteers were trained and administered by a small cadre of professional full-time officers under the command of the Commandant Royal Observer Corps; latterly a serving RAF Air Commodore.
In 1925, following a Defence Committee initiative undertaken the previous year, the formation of an RAF command concerning the Air Defence of Great Britain led to the provision of a Raid Reporting System, itself delegated to a sub-committee consisting of representatives from the Air Ministry, Home Office and the General Post Office. This Raid Reporting System was to provide for the visual detection, identification, tracking and reporting of aircraft over Great Britain, and was eventually to become known as the Observer Corps. The Observer Corps was subsequently awarded the title Royal by His Majesty King George VI in April 1941, in recognition of service carried out by Observer Corps personnel during the Battle of Britain.
Throughout the remainder of the Second World War, the ROC continued to complement and at times replace the Chain Home defensive radar system by undertaking an inland aircraft tracking and reporting function, while Chain Home provided a predominantly coastal, long-range tracking and reporting system. With the advent of the Cold War, the ROC continued in its primary role of aircraft recognition and reporting, and in 1955 was allocated the additional task of detecting and reporting nuclear explosions and associated fall-out. By 1965, thanks to advances in (radar) technology, most roles and responsibilities relating to aircraft had been withdrawn and the ROC assumed the role of field force for the United Kingdom Warning and Monitoring Organisation (UKWMO); a role which the ROC continued until the early 1990s and the cessation of the Cold War.
On Saturday 10 May 1941, ROC posts in the Durham, Galashiels and Glasgow Groups were responsible for tracking and reporting what transpired to be the arrival of Rudolph Hess. The aircraft was first heard and reported by Durham post A2 Embleton, it was then seen as a silhouette in the moonlight by post A3 Chatton and correctly identified as a ME110. The controller at No 13 Group Fighter Command refused to accept that it was a ME110 because of its limited range and suggested that it must be a Dornier 17. The aircraft continued on its westerly course and was seen briefly by the observers at F2 Jedburgh and G1 Ashkirk who reported it as a ME110, the track was lost for a time over the unobserved forest of Ettrick. The aircraft was next seen and reported by post G3 West Kilbride as a ME110, a few minutes later post H2 Eaglesham reported seeing someone bale out, the aircraft crashed close to the Eaglesham post and the rest is history.
In September 1941, due to the increased call-up of manpower, women were admitted to the Corps, as in all other branches of the Services they did sterling work and acquitted themselves with distinction.
In addition to reporting all aircraft flying over land, or the sea belt adjoining the coastline, ROC personnel on duty also assisted aircraft that were lost or in distress. To achieve this, personnel at selected observation posts were issued with TR9D HF short-range radio sets (code named Darky) and on receipt of an aircraft distress call, they would if possible make contact and give the ROC post location. If the aircraft required to land immediately, the observers would advise a course to steer to the nearest airfield or landing ground. Other selected ROCposts located near mountainous terrain would light red flares to warn aircraft if they were in danger of flying into high ground, the code name for this operation was (Granite). The combined efforts of Darky and Granite saved a great many allied aircraft and their crews.
During the final stages of hostilities, concern was expressed at the number of friendly aircraft being shot down by the Royal Naval anti-aircraft gunners and as a result, a call went out for volunteers from the ROC to man the Defensively Equipped Merchant Ships (DEMS) to identify aircraft during the D-Day Landings. The scheme was known as ‘SEABORNE’ and the volunteers temporarily joined the Royal Navy with the rank of Petty Officer/Aircraft Identifier. These volunteers continued to wear ROC uniform, but wore SEABORNE shoulder flashes and a Royal Navy brassard with the letters RN. Twenty two Seaborne observers survived their ships being sunk, two lost their lives and a number were injured. The Seaborne adventure was an unqualified success and in recognition of this, His Majesty King George Vl approved the wearing of the SEABORNE flash as a permanent feature of the uniform; in addition, ten Seaborne members were mentioned in despatches. Today there is a Seaborne Observers’ Association, of which Air Vice-Marshal G P Black CB OBE AFC RAF (Rtd) is the honorary President.
At the cessation of hostilities, the ROCwas stood down in May 1945."
http://www.rocassoc.org/open/national/roca/hist_ng2.htm
https://en.wikipedia.org/wiki/Royal_Observer_Corps
http://www.historylearningsite.co.uk/world-war-two/world-war-two-in-western-europe/battle-of-britain/the-observer-corps/
http://www.bbc.co.uk/history/ww2peopleswar/stories/16/a4282616.shtml
http://www.bbc.co.uk/history/ww2peopleswar/stories/54/a8470154.shtml
http://cyclopstv.co.uk/productions/sentinels-of-britain/ .
https://youtu.be/0NbJ7HqLPRU?t=12m9s .
Two men of the Royal Observer Corps on a cliff top near Dover, 1943.
Throughout the remainder of the Second World War, the ROC continued to complement and at times replace the Chain Home defensive radar system by undertaking an inland aircraft tracking and reporting function, while Chain Home provided a predominantly coastal, long-range tracking and reporting system. With the advent of the Cold War, the ROC continued in its primary role of aircraft recognition and reporting, and in 1955 was allocated the additional task of detecting and reporting nuclear explosions and associated fall-out. By 1965, thanks to advances in (radar) technology, most roles and responsibilities relating to aircraft had been withdrawn and the ROC assumed the role of field force for the United Kingdom Warning and Monitoring Organisation (UKWMO); a role which the ROC continued until the early 1990s and the cessation of the Cold War.
The Royal Observer Corps was a uniformed volunteer organisation, which has enjoyed a long association with the Royal Air Force. The badge of the Royal Observer Corps depicts a beacon lighter of Elizabethan times; these beacon-lighters were recruited from the local population and were organised and paid for by the County Sheriff, to care for and light the warning beacons in the event of approaching danger. The motto of the Royal Observer Corps is: "Forewarned is Forearmed"
With the passing of years, the political situation in Europe deteriorated and in January 1935, the Boyd Committee recommended that the Observer Corps should expand in four stages. It was in 1936 that the Corps became part of the newly formed Fighter Command under Lord Dowding and moved its headquarters to RAF Bentley Priory, Stanmore, Middlesex. From this time until the start of World War ll, new Observer Corps Groups were rapidly formed and on 24 August 1939, when the Corps was mobilised, the greater part of the country was covered by Observer Corps posts.
With the passing of years, the political situation in Europe deteriorated and in January 1935, the Boyd Committee recommended that the Observer Corps should expand in four stages. It was in 1936 that the Corps became part of the newly formed Fighter Command under Lord Dowding and moved its headquarters to RAF Bentley Priory, Stanmore, Middlesex. From this time until the start of World War ll, new Observer Corps Groups were rapidly formed and on 24 August 1939, when the Corps was mobilised, the greater part of the country was covered by Observer Corps posts.
The Corps won its spurs during the Battle of Britain and in his despatch, Lord Dowding said, “ It is important to note that, at this time the Observer Corps constituted the whole means of tracking enemy raids once they had crossed the coastline, their work throughout was quite invaluable, without it, air raid warning systems could not have been operated and inland interceptions would rarely have been made.
Because the RDF of 1940 was useless once the Luftwaffe had crossed the coast, all inland sightings were passed from a network of Observer Corps posts to their group control centre, thence to the Filter Room and Control Room. Plots were triangulated before being passed up the chain to Fighter Command via RAF sector controls. In recognition of the invaluable work done by the Observer Corps, an announcement was made in the House of Commons on 9 April 1941 that, His Majesty King George Vl had granted the Corps the title “Royal”. It was the only organisation so honoured during the war years.
On Saturday 10 May 1941, ROC posts in the Durham, Galashiels and Glasgow Groups were responsible for tracking and reporting what transpired to be the arrival of Rudolph Hess. The aircraft was first heard and reported by Durham post A2 Embleton, it was then seen as a silhouette in the moonlight by post A3 Chatton and correctly identified as a ME110. The controller at No 13 Group Fighter Command refused to accept that it was a ME110 because of its limited range and suggested that it must be a Dornier 17. The aircraft continued on its westerly course and was seen briefly by the observers at F2 Jedburgh and G1 Ashkirk who reported it as a ME110, the track was lost for a time over the unobserved forest of Ettrick. The aircraft was next seen and reported by post G3 West Kilbride as a ME110, a few minutes later post H2 Eaglesham reported seeing someone bale out, the aircraft crashed close to the Eaglesham post and the rest is history.
In September 1941, due to the increased call-up of manpower, women were admitted to the Corps, as in all other branches of the Services they did sterling work and acquitted themselves with distinction.
In addition to reporting all aircraft flying over land, or the sea belt adjoining the coastline, ROC personnel on duty also assisted aircraft that were lost or in distress. To achieve this, personnel at selected observation posts were issued with TR9D HF short-range radio sets (code named Darky) and on receipt of an aircraft distress call, they would if possible make contact and give the ROC post location. If the aircraft required to land immediately, the observers would advise a course to steer to the nearest airfield or landing ground. Other selected ROCposts located near mountainous terrain would light red flares to warn aircraft if they were in danger of flying into high ground, the code name for this operation was (Granite). The combined efforts of Darky and Granite saved a great many allied aircraft and their crews.
During the final stages of hostilities, concern was expressed at the number of friendly aircraft being shot down by the Royal Naval anti-aircraft gunners and as a result, a call went out for volunteers from the ROC to man the Defensively Equipped Merchant Ships (DEMS) to identify aircraft during the D-Day Landings. The scheme was known as ‘SEABORNE’ and the volunteers temporarily joined the Royal Navy with the rank of Petty Officer/Aircraft Identifier. These volunteers continued to wear ROC uniform, but wore SEABORNE shoulder flashes and a Royal Navy brassard with the letters RN. Twenty two Seaborne observers survived their ships being sunk, two lost their lives and a number were injured. The Seaborne adventure was an unqualified success and in recognition of this, His Majesty King George Vl approved the wearing of the SEABORNE flash as a permanent feature of the uniform; in addition, ten Seaborne members were mentioned in despatches. Today there is a Seaborne Observers’ Association, of which Air Vice-Marshal G P Black CB OBE AFC RAF (Rtd) is the honorary President.
At the cessation of hostilities, the ROCwas stood down in May 1945."
http://www.rocassoc.org/open/national/roca/hist_ng2.htm
https://en.wikipedia.org/wiki/Royal_Observer_Corps
http://www.historylearningsite.co.uk/world-war-two/world-war-two-in-western-europe/battle-of-britain/the-observer-corps/
http://www.bbc.co.uk/history/ww2peopleswar/stories/16/a4282616.shtml
http://www.bbc.co.uk/history/ww2peopleswar/stories/54/a8470154.shtml
http://cyclopstv.co.uk/productions/sentinels-of-britain/ .
https://youtu.be/0NbJ7HqLPRU?t=12m9s .
(Royal) Observer Corps I can see for miles and miles ....
"On a clear day, you can see for miles and miles and miles.
The old saying turns out to be just about true. For a six-foot tall person, the horizon is a little more than 3 miles (5 km) away.
Geometry tells us that the distance of the horizon – i.e. the farthest point the eye can see before Earth curves out beneath our view – depends simply on the height of the observer. For example, if you stood atop Mount Everest (which is 29,029 feet, or 8,848 meters tall), the horizon would be about 230 miles (370 km) away."
http://www.livescience.com/32111-how-far-away-is-the-horizon.html
"Dust, water vapour and pollution in the air will rarely let you see more than 20 kilometres (12 miles), even on a clear day. Often, the curvature of the Earth gets in the way first – eg at sea level, the horizon is only 4.8 kilometres (2.9 miles) away. On the top of Mt Everest, you could theoretically see for 339 kilometres (211 miles), but in practice cloud gets in the way. For a truly unobstructed view though, look up. On a clear night, you can see the Andromeda galaxy with the naked eye, which is 2.25 million light years away."
http://www.howitworksdaily.com/what-is-the-maximum-distance-the-human-eye-can-see-if-unobstructed/
"The short answer is that a person of average height can see almost three miles at sea level, actually 2.8 miles to be exact. However, that answer assumes that the person's eyes are at six feet above sea level and the conditions are near perfect.
For a more thorough, you might want to look at what John Rousmaniere has written in his very useful tome, The Annapolis Book of Seamanship, but I'll summarize that here. In his chapter on navigation aids, he explains two ranges of visibility. One he terms the "nominal range of visibility," and the other the "geographic range of visibility." The former, says Rousmaniere, relates to the visibility of the light from a lighthouse, for instance. A light from a lighthouse may be bright enough to have a nominal range of visibility that measures 13 miles, but its geographic range of visibility—the distance at which you can actually see the lighthouse—would be much smaller. You can find a standard table of distances listed in Rousmaniere's book on page 214, with references to the height off the water required to see those distances.
The kind of visibility that you're asking about—geographical visibility—refers to the distance at which any object can be seen. This distance is limited by the curvature of the earth, and it's greatly influenced by height. Of course atmospheric conditions will also influence this distance, but for the purposes of this explanation let's just assume they are perfectly clear: no clouds, no haze, no smog. Let's say same the same hypothetical lighthouse is 50 feet tall. According to Rousmaniere's table, it would only be visible for 8.1 miles. Now, if you were standing on deck aboard a medium-sized sailboat and you were of average height, that would put your eyes about 10 feet off the water. From that vantage point, you should be able see 3.6 nautical miles, but you could see the light house at a distance of 11.7 n.m. (According to Rousmaniere's table, the 50-foot-high lighthouse is visible for 8.1 n.m. Combine that with your geographic range of visibility at 10 feet above sea level [3.6 n.m.] and you get a distance of 11.7 n.m.)
So whoever told you that you should be able to see the horizon from the shore 13 miles away was mistaken. If you could climb a 130-foot tower, then yes, you could see 13.1 miles out to sea. Or if the object at sea was 125 feet off the water, then you should be able to see it from a shoreline 13 miles away (125 feet added to your own five-or-so feet of height)."
http://www.sailnet.com/forums/cruising-articles/20525-sea-level-visibility.html .
"On a clear day, you can see for miles and miles and miles.
The old saying turns out to be just about true. For a six-foot tall person, the horizon is a little more than 3 miles (5 km) away.
Geometry tells us that the distance of the horizon – i.e. the farthest point the eye can see before Earth curves out beneath our view – depends simply on the height of the observer. For example, if you stood atop Mount Everest (which is 29,029 feet, or 8,848 meters tall), the horizon would be about 230 miles (370 km) away."
http://www.livescience.com/32111-how-far-away-is-the-horizon.html
"Dust, water vapour and pollution in the air will rarely let you see more than 20 kilometres (12 miles), even on a clear day. Often, the curvature of the Earth gets in the way first – eg at sea level, the horizon is only 4.8 kilometres (2.9 miles) away. On the top of Mt Everest, you could theoretically see for 339 kilometres (211 miles), but in practice cloud gets in the way. For a truly unobstructed view though, look up. On a clear night, you can see the Andromeda galaxy with the naked eye, which is 2.25 million light years away."
http://www.howitworksdaily.com/what-is-the-maximum-distance-the-human-eye-can-see-if-unobstructed/
"The short answer is that a person of average height can see almost three miles at sea level, actually 2.8 miles to be exact. However, that answer assumes that the person's eyes are at six feet above sea level and the conditions are near perfect.
For a more thorough, you might want to look at what John Rousmaniere has written in his very useful tome, The Annapolis Book of Seamanship, but I'll summarize that here. In his chapter on navigation aids, he explains two ranges of visibility. One he terms the "nominal range of visibility," and the other the "geographic range of visibility." The former, says Rousmaniere, relates to the visibility of the light from a lighthouse, for instance. A light from a lighthouse may be bright enough to have a nominal range of visibility that measures 13 miles, but its geographic range of visibility—the distance at which you can actually see the lighthouse—would be much smaller. You can find a standard table of distances listed in Rousmaniere's book on page 214, with references to the height off the water required to see those distances.
The kind of visibility that you're asking about—geographical visibility—refers to the distance at which any object can be seen. This distance is limited by the curvature of the earth, and it's greatly influenced by height. Of course atmospheric conditions will also influence this distance, but for the purposes of this explanation let's just assume they are perfectly clear: no clouds, no haze, no smog. Let's say same the same hypothetical lighthouse is 50 feet tall. According to Rousmaniere's table, it would only be visible for 8.1 miles. Now, if you were standing on deck aboard a medium-sized sailboat and you were of average height, that would put your eyes about 10 feet off the water. From that vantage point, you should be able see 3.6 nautical miles, but you could see the light house at a distance of 11.7 n.m. (According to Rousmaniere's table, the 50-foot-high lighthouse is visible for 8.1 n.m. Combine that with your geographic range of visibility at 10 feet above sea level [3.6 n.m.] and you get a distance of 11.7 n.m.)
So whoever told you that you should be able to see the horizon from the shore 13 miles away was mistaken. If you could climb a 130-foot tower, then yes, you could see 13.1 miles out to sea. Or if the object at sea was 125 feet off the water, then you should be able to see it from a shoreline 13 miles away (125 feet added to your own five-or-so feet of height)."
http://www.sailnet.com/forums/cruising-articles/20525-sea-level-visibility.html .
Post Plotting Instrument & Micklethwait Height Corrector
'‘The Observer Instrument Mk 2A, designed by an Engineer named Captain Ball of Hampshire. Part of the instrument comprised ‘The Micklethwait Height Correction Attachment’, which allowed for heights to be corrected between two posts plotting the same aircraft.
The Correction Height Procedure was as follows :-
1. An observer estimated the height of an aircraft and set the height on the height bar.
2. The aircraft was sighted and the grid position shown by the instrument pointer was reported to the Ops Room. It should be noted that the aircraft grid position was only as accurate as the accuracy of the estimated height. It was necessary for at least one other post to carryout this procedure as well.
3. Using cross plotting the Ops Room plotter could ascertain the true position of the aircraft and he would quickly inform the posts of this grid position.
4. The post observer would then slide the Micklethwait cranked pointer on to the true grid position and read off the true height of the aircraft on the Micklethwait Height bar. This would then be set on the instrument height bar for all subsequent plots.
http://www.rocassoc.org/open/items/09/mickle.htm
http://www.roc-heritage.co.uk/post-instrument.html
http://www.roc-heritage.co.uk/uploads/7/6/8/9/7689271/use_of_post_instrument.pdf
https://en.wikipedia.org/wiki/Post_Instrument
http://www.roc-heritage.co.uk/operations-centre-clock.html
http://www.roc-heritage.co.uk/aircraft-recognition.html
OC New Forest
https://youtu.be/0NbJ7HqLPRU?t=12m9s .
'‘The Observer Instrument Mk 2A, designed by an Engineer named Captain Ball of Hampshire. Part of the instrument comprised ‘The Micklethwait Height Correction Attachment’, which allowed for heights to be corrected between two posts plotting the same aircraft.
The Correction Height Procedure was as follows :-
1. An observer estimated the height of an aircraft and set the height on the height bar.
2. The aircraft was sighted and the grid position shown by the instrument pointer was reported to the Ops Room. It should be noted that the aircraft grid position was only as accurate as the accuracy of the estimated height. It was necessary for at least one other post to carryout this procedure as well.
3. Using cross plotting the Ops Room plotter could ascertain the true position of the aircraft and he would quickly inform the posts of this grid position.
4. The post observer would then slide the Micklethwait cranked pointer on to the true grid position and read off the true height of the aircraft on the Micklethwait Height bar. This would then be set on the instrument height bar for all subsequent plots.
http://www.rocassoc.org/open/items/09/mickle.htm
http://www.roc-heritage.co.uk/post-instrument.html
http://www.roc-heritage.co.uk/uploads/7/6/8/9/7689271/use_of_post_instrument.pdf
https://en.wikipedia.org/wiki/Post_Instrument
http://www.roc-heritage.co.uk/operations-centre-clock.html
http://www.roc-heritage.co.uk/aircraft-recognition.html
OC New Forest
https://youtu.be/0NbJ7HqLPRU?t=12m9s .
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