Showing posts with label RDF. Show all posts
Showing posts with label RDF. Show all posts

Sunday, September 27, 2020

Bristol Beaufighter - nightfighter of 219


Bristol Beaufighter

Nightfighter radar
Big Ego versus Dowding; nightfighters > .

Bristol Beaufighter nightfighter & Sq 219
http://www.aviation-history.com/bristol/beaufite.html
http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=135

No. 219 Squadron Royal Air Force: formed Catterick, October 1939, flying Blenheims. Converted to Beaufighters in October 1940. From February 1944 flew Mosquitos.

Catterick. 4th Oct 1939 to 12 Oct 1940 & 25 Apr 1943 14 May 1945
Redhill 12 Oct 1940 to 12 Dec 1940.
Tangmere. 12 Dec 1940 to 23 June 1942.
Acklington. 23 June 1942 to 21 Oct 1942
Scorton 21 Oct 1942 to 25 Apr 1943
Bone 14 May 1945 to ?
Sidi Amor. ? to 27 Feb 1944
Woodvale 27 Feb 1944 to 15 Mar 1944
Honiley 15 Mar 1944 to 1 Apr 1944
Bradwell Bay. 1 Apr 1944 to 29 Aug 1944
Hunsdon. 29 Aug 1944 to 10 Oct 1944
Amiens, B48. from 10 Oct 1944
http://www.wartimememoriesproject.com/ww2/allied/royalairforce/sqdview.php?pid=417

Through most of the Second World War and the 1950s No. 219 Squadron of the Royal Air Force operated as a night fighter air defence squadron. Three commanders of the squadron went on to be Chiefs of the Air Staff, two of the RAF and one of the Royal Pakistani Air Force.

It reformed in October 1939, shortly after the outbreak of the Second World War, operating Bristol Blenheims from RAF Catterick. Whilst it was intended to carry out shipping protection missions, it began to be used as a night fighter unit after becoming fully operational in February 1940; in October, it was moved to RAF Redhill, near London, and converted to the Bristol Beaufighter.

In December 1940, it moved to RAF Tangmere in Sussex, continuing in its operational role.

It moved back to north England in mid 1942, to RAF Acklington and later RAF Scorton; in May 1943, the squadron was transferred to North Africa, where it was dispersed between various ports to provide night fighter defence. In September 1943 it operated a number of aircraft from Sicily, but moved back to the UK in January 1944 to join the newly forming Second Tactical Air Force in preparation for the invasion of Normandy. It re-equipped with de Havilland Mosquito night fighters, first Mk. 17 and later Mk. 30 models, and flew intruder missions over north-western Europe from RAF Woodvale, RAF Honiley, RAF Bradwell Bay and RAF Hunsdon. It moved to bases in France in October 1944, returning to the UK after the end of hostilities in August 1945, and was disbanded in September 1946.
https://en.wikipedia.org/wiki/No._219_Squadron_RAF

42-6-12 Daring Solo Beaufighter Raid - Paris 1942 > .
Operation Squabble, a daring British plan to raise the morale of the people of occupied Paris by dropping a French tricolour on the Arc de Triomphe.

Historical: Beaufighter attack on a German ship: WW2 pilot Steve Stevens DFC
https://www.youtube.com/watch?v=hL4_z3kWa3s

Semi-historical campaign dealing with the Beaufighters operated by the RAF in 1942, in Μalta and the North African region.
https://www.youtube.com/watch?v=cj-0Fork_rE
at No comments:
Labels: , , , ,

Bristol Blenheim - nightfighters

.https://www.youtube.com/watch?v=hipWoINtJX0 > . 
A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time post-World War II) is a fighter aircraft adapted for use at night or in other times of bad visibility.

Bristol Blenheim
In the German night-bombing raid on London on 18 June 1940, Blenheims accounted for five German bombers, thus proving that they were better-suited for night fighting. In July, No. 600 Squadron, by then based at RAF Manston, had some of its Mk IFs equipped with AI Mk III radar. With this radar equipment, a Blenheim from the Fighter Interception Unit (FIU) at RAF Ford achieved the first success on the night of 2–3 July 1940, accounting for a Dornier Do 17 bomber. More successes came, and before long the Blenheim proved itself invaluable as a night fighter. Gradually, with the introduction of the Bristol Beaufighter in 1940–1941, the Blenheim was supplanted by its faster, better-armed descendant.
https://en.wikipedia.org/wiki/Bristol_Blenheim
http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=293

Night Fighter Aircraft
http://www.militaryfactory.com/aircraft/nightfighter-aircraft.asp

Night fighters began to be used in World War I and included types that were specifically modified to operate at night.

During World War II, night fighters were either purpose-built or day fighters modified to be effective night fighting combat aircraft, often employing radar or other systems for providing some sort of detection capability in low visibility. Many WW II night fighters also included instrument landing systems for landing at night as turning on the runway lights made runways into an easy target for opposing intruders.

Avionics systems were greatly miniaturized over time allowing the addition of radar altimeter, terrain-following radar, improved instrument landing system (ILS), microwave landing system (MLS), Doppler weather radar, LORAN receivers, GEE, tactical air navigation system (TACAN), inertial navigation system (INS), GPS, and GNSS in aircraft. The addition of greatly improved landing and navigation equipment combined with radar led to the use of the term all-weather fighter or all-weather fighter attack, depending on the aircraft capabilities. The use of the term night fighter gradually faded away as a result of these improvements making the vast majority of fighters capable of night operation.

The Nazis invaded Poland on 1 September 1939, and by this time, the RAF were well advanced with plans to build a radar – then called 'RDF' in Britain – equipped night-fighter fleet. The Airborne Interception Mk. II radar (AI Mk. II) was being fit experimentally to a small number of Bristol Blenheim aircraft, having been selected for this role as its fuselage was sufficiently roomy to accommodate the additional crew member and radar apparatus; the first prototype system went into service in November 1939, long before the opening of major British operations. These early systems had significant practical problems, and while work was underway to correct these flaw, by the time the Blitz opened in August 1940, the night fighter fleet was still in its infancy.

Through this period, the RAF experimented with many other aircraft and interception methods in an effort to get a working night fighter force. One attempt to make up for the small number of working radars was to fit an AI to a Douglas Havoc bomber which also carried a searchlight in its nose. These Turbinlite aircraft were intended to find the targets and illuminate them with the searchlight, allowing Hurricanes adapted for night flying to shoot them down visually. This proved almost impossible to arrange in practice, and the Cat Eye fighters had little luck during the closing months of 1940. The Turbinlite squadrons were disbanded in early 1943.

By early 1941, the first examples of a production-quality radar, AI Mk. IV, were beginning to arrive. This coincided with the arrival of the Beaufighter, which offered significantly higher performance than the pre-war Blenheims; it was the highest performance aircraft capable of carrying the bulky early airborne interception radars used for night fighter operations, and quickly became invaluable as a night fighter. Over the next few months, more and more Beaufighters arrived and the success of the night fighters roughly doubled every month until May '41, when the Luftwaffe ended their bombing efforts. Although night bombing never ended, its intensity was greatly decreased, giving the RAF time to introduce the AI Mk. VIII radar working in the microwave band, and the de Havilland Mosquito to mount it. This combination remained the premier night fighter until the end of the war.

As the German effort wound down, the RAF's own bombing campaign was growing. The Mosquitos had little to do over the UK, so a number of squadrons were formed within No. 100 Group RAF and fit with special systems, such as Perfectos and Serrate, for homing-in on German night fighters. The British also experimented with mounting pilot-operated AI Mark 6 radar sets in single-seat fighters, and the Hurricane II C(NF), a dozen of which were produced in 1942, became the first radar-equipped, single-seat night fighter in the world. It served with 245 and 247 Squadrons briefly and unsuccessfully before being sent to India to 176 Squadron, with which it served until the end of 1943. A similarly radar-equipped Hawker Typhoon was also developed, but no production followed.

at No comments:
Labels: , , ,

Friday, November 1, 2019

40-7-10 Battle of Britain Begins

The Battle of Britain was a military campaign of the Second World War, in which the Royal Air Force (RAF) defended the United Kingdom (UK) against large-scale attacks by Nazi Germany's air force, the Luftwaffe. It has been described as the first major military campaign fought entirely by air forces. The British officially recognise the battle's duration as being from 10 July until 31 October 1940, which overlaps the period of large-scale night attacks known as The Blitz, that lasted from 7 September 1940 to 11 May 1941. German historians do not accept this subdivision and regard the Luftschlacht um England (Air Battle for England) as a single campaign lasting from July 1940 to June 1941, including the Blitz.


The Kanalkampf (Channel fight) was the German term for air operations by the Luftwaffe against the British Royal Air Force (RAF) over the English Channel in July 1940. The air operations over the channel began the Battle of Britain during the Second World War. By 25 June, the Allies had been defeated in Western Europe and Scandinavia. Britain rejected peace overtures and on 16 July, Adolf Hitler issued Directive 16 to the Wehrmacht (German armed forces), ordering preparations for the invasion of Britain, under the codename Unternehmen Seelöwe (Operation Sea Lion).

The Germans needed air superiority over southern England before the invasion and the Luftwaffe was to destroy the RAF, assume command of the skies and protect the cross-channel invasion from the Royal Navy. To engage RAF Fighter Command, the Luftwaffe attacked convoys in the English Channel. ... British and German writers and historians acknowledge that air battles were fought over the Channel between the Battle of France and Battle of Britain; deliberate German attacks against British coastal targets and convoys began on 4 July. During the Kanalkampf, the Luftwaffe received modest support from shore artillery and the E-Boats of the Kriegsmarine (German navy).

Fighter Command could not protect adequately the convoys; the Germans sank several British and neutral ships and shot down a considerable number of British fighters. The Royal Navy was forced to suspend the sailing of large convoys in Channel waters and close it to ocean-going vessels until more protection could be arranged, which took several weeks. On 1 August, Hitler issued Directive 17, extending Luftwaffe operations to the British mainland and RAF-related targets and on Adlertag (Eagle Day, 13 August) the main air offensive against the RAF began. The Kanalkampf had drawn out Fighter Command as intended and convoy attacks continued for several more days. Both sides had suffered losses but the Luftwaffe failed to inflict a decisive defeat on Fighter Command and the RAF; the Luftwaffe had yet to gain air superiority for Operation Sea Lion.

Directive 17, August 1, 1940, Battle of Britain, Full text .
https://en.wikipedia.org/wiki/List_of_Adolf_Hitler%27s_directives .

ASV AI RDF ..
Battle of Britain & RDF ..
Blitz ..
Bomb Sight Site ..
at No comments:
Labels: , , , , , , , , , , , , , ,

Saturday, September 28, 2019

ASV AI RDF

https://youtu.be/uTE-jHVIKJU?t=26m39s
Bizarre Origins of Radar Technology - Time > .
at No comments:
Labels: , , , ,

Friday, September 27, 2019

Battle of Britain & RDF

Battle of Britain - The WW2 Battle That Gave Us Radar > .
Battle of Britain and Artie Holmes' Hurricane - HiGu > . 
at No comments:
Labels: , , , , , , , , ,

Thursday, September 19, 2019

Ju-88s + radar captured

Luftwaffe Defection 43-5-9 > .
Ju-88 nightfighter with FuG-202 Lichtenstein radar.

Big Ego versus Dowding; nightfighters > .

https://en.wikipedia.org/wiki/Junkers_Ju_88 .
https://en.wikipedia.org/wiki/Lichtenstein_radar .
https://en.wikipedia.org/wiki/Night_fighter .
at No comments:
Labels: , , , , ,

Wednesday, September 18, 2019

Kammhuber Line

Kammbuber Line & German Radar > .
Operation Biting - Raid on Bruneval - tnh > .

The Kammhuber Line was the Allied name given to the German night air defense system established in July 1940 by Colonel Josef Kammhuber. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fighter. Each sector would direct the night fighter into visual range with target bombers.

The Line was very effective against early Bomber Command tactics. However, the German method was analyzed by the RAF and a counter measure developed. On the night of 30/31 May 1942 in its 1,000 plane raid against Cologne Bomber Command introduced the use of the bomber stream. The concentration of bombers through a few of the boxes resulted in the defenses being overwhelmed. In response, the Germans converted their ground radar into a radar network, which would follow the path of the British bombers, while a controller directed the night fighters into the stream. Measure and counter measure continued until October 1944, when German defenses were no longer able to respond..........

When Germany organised its air defences into the Kammhuber Line, it was realised by the British (Bomber Command's Operational Research Section (BC-ORS)) that if the RAF bombers were to fly in a bomber stream they could overwhelm the night fighters who flew in individual cells directed to their targets by ground controllers. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses.

British intelligence soon discovered the nature of the Kammhuber Line and started studying ways to defeat it. At the time RAF Bomber Command sent in their planes one at a time to force the defenses to be spread as far apart as possible, meaning that any one aircraft had to deal with little concentrated flak. This also meant the Himmelbett centres were only dealing with perhaps one or two planes at a time, making their job much easier.

At the urging of R.V. Jones, Bomber Command reorganized their attacks into streams of bombers – the so-called Bomber stream, carefully positioned so the stream flew down the middle of a single cell. Data provided to the British scientists allowed them to calculate that the bomber stream would overwhelm the six potential interceptions per hour that the German "Tame Boar" (Zahme Sau) night fighters could manage in a Himmelbett zone. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses. The introduction of Gee radio navigation in 1942 allowed the RAF bombers to fly by a common route and at the same speed to and from the target, each aircraft being allotted a height band and a time slot in a bomber stream to minimize the risk of collision. The first use of the bomber stream was the first 1,000 bomber raid against Cologne on the night of 30/31 May 1942. This tactic was extremely effective, leading to fighting between Kammhuber and Erhard Milch, his boss.

Although the success rate of the Line dropped, the network of radars and plotting stations continued to prove their worth. Now when a raid started, night fighters from any base within range were directed into the stream, where it was hoped they would be able to find aircraft with their radar. At the same time a massive building program started to add hundreds of Würzburgs to the system, although the infrastructure needed was extensive. The boxes were initially the radius of the Würzburg radars, about 22 miles, but more powerful radar later on made the boxes up to 100 miles across. Eventually, the line of boxes was several deep, especially around larger towns and the Ruhr valley. Once again the system started to score increasing successes against the British raids.

The British were ready for this development, and as soon as the rates started to improve – for the Germans – they introduced "Window". Dropping strips of foil from a number of "lead" bombers, the German radar operators saw what appeared to be a stream entering their box, each packet of chaff appearing to be a bomber on their displays. Night fighters were then sent to attack this stream, only to find empty space. Just as the fighters reached the false stream, the "real" stream appeared hundreds of miles away, too far to be attacked. The first time this was used was during Operation Gomorrah (a week-long bombing campaign against Hamburg) and proved spectacularly effective. The German radar operators eventually learned to spot the lead bombers at the edge of the windowing, making it less effective. The British had held back from introducing Window for over a year lest the technique be adopted by the Germans and used against British cities.

A more sophisticated method for blinding the German radar was "Mandrel", a jamming signal broadcast from aircraft accompanying the bomber stream or later certain bombers themselves. This progressed into jamming techniques against individual German radar types and spoofing radars to see bomber streams that weren't there. The British also attacked the communications between ground stations and fighters, with Operation Corona, broadcasting false directions in authentic accents over the radio.

One other element was long-range nightfighters operating against the German nightfighters, using a system called "Serrate" to home in on the German nightfighter radar signals. At least three squadrons equipped with Bristol Beaufighter and de Havilland Mosquito were part of No. 100 Group RAF supporting Bomber Command with electronic countermeasures.

https://en.wikipedia.org/wiki/Operations_research
.......
The Line was very effective at first, but was soon rendered useless by a simple change in tactics. The RAF directed all of its bombers to fly in a single stream, overwhelming the sectors, who could only intercept a single aircraft at a time. This led to a dramatic drop in interception rates compared to the raid size. The Line was eventually turned into a radar network, and the night fighters improved with their own radar sets to allow them to hunt on their own.
https://en.wikipedia.org/wiki/Kammhuber_Line .
at No comments:
Labels: , , , , , ,

Friday, September 13, 2019

Polyethylene, radar, and submarine cables

.
Undersea Cables, Pipelines - Naval Gazing >> .

Polyethylene, radar, and submarine cables

Communication infrastructure ..

"They had heated a mixture of ethylene and benzaldehyde to 170°C (338°F), using apparatus that could submit materials to a pressure of 1,900 atmospheres (1,925 bars). But the reactions were explosive and safety concerns prompted the now defunct ICI, which merged into Dutch-based Akzo Nobel, to halt the research.

In December that year, Williams and colleagues Michael Perrin and John Paton reinvestigated the experiments of Gibson and Fawcett using ethylene alone. Under similar experimental conditions - but with better equipment - they observed a pressure drop, and when the reaction finished there were 8.5g of white PE powder.

Williams, Perrin and Paton had been lucky. The vessel had leaked and, it was later confirmed, a trace of oxygen was present in the fresh ethylene that had been added to the reaction vessel to replace the leaked gas. The fresh ethylene contained, by chance, the right amount of oxygen to act as an initiator.

"For once it didn't explode - usually it did - and we thought something must be wrong. So we left it to cool overnight. And when I looked inside the metal container the next day, I found what looked like a lump of sugar. In fact, that 'sugar' was polythene."

Uses for early PE were limited, as the material was soft and had a low melting point. This was because under the high pressure polymerization process the ethylene molecules did not always add in a regular chain.

A member of ICI's dyestuffs division, Bernard Habgood, recognized that PE could supersede gutta-percha, a natural material, for insulation of submarine cables. This provided the impetus to proceed to commercial scale production. The first full-scale PE plant, with a 100 tonne/year capacity, went into production on September 1, 1939, the day Germany invaded Poland and war became unavoidable for Britain.

ICI's work on PE changed during the Second World War, when the material was used to insulate airborne radar equipment. During the development of radar in the early war years it had proved difficult to insulate the equipment to prevent power loss and thus preserve the strength of the signal. PE's electrical insulation properties enabled the British forces to reduce the weight of radar equipment and allowed them to place radars inside fighter planes. This provided an enormous technical advantage in long-distance warfare, most significantly in the Battle of the Atlantic against German submarines. The Germans were obliged to use a bulkier insulating material for their radar, which was less effective."
http://www.icis.com/resources/news/2008/05/12/9122447/polyethylene-discovered-by-accident-75-years-ago/

https://en.wikipedia.org/wiki/Polyethylene
http://www.polymer-search.com/inventionplastic.html
http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/polypropylene.html

http://www.independent.co.uk/news/science/polythenes-story-the-accidental-birth-of-plastic-bags-800602.html .
at No comments:
Labels: , , , , , ,

Wednesday, September 11, 2019

Radio Direction Finding

https://www.youtube.com/watch?v=uBg45ro5MpU > .
Plane Safety (1938) > .

at No comments:
Labels: , , , , , , , ,

RDF

Scanning Chain Home Installations - The Last Zeppelin Raid 1939 - mfp > .


Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s). Radio waves (pulsed or continuous) from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.

Radar was developed secretly for military use by several nations in the period before and during World War II. The term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging. The term radar has since entered English and other languages as a common noun, losing all capitalization.

The modern uses of radar are highly diverse, including air and terrestrial traffic control, radar astronomy, air-defence systems, antimissile systems, marine radars to locate landmarks and other ships, aircraft anticollision systems, ocean surveillance systems, outer space surveillance and rendezvous systems, meteorological precipitation monitoring, altimetry and flight control systems, guided missile target locating systems, ground-penetrating radar for geological observations, and range-controlled radar for public health surveillance. High tech radar systems are associated with digital signal processing, machine learning and are capable of extracting useful information from very high noise levels.

Other systems similar to radar make use of other parts of the electromagnetic spectrum. One example is "lidar", which uses ultraviolet, visible, or near infrared light from lasers rather than radio waves.

http://www.bbc.co.uk/history/topics/radar

https://www.youtube.com/watch?v=BSajdavR6Yw >


RADAR
Naval (ASV) and airborne (AI) RADAR
https://youtu.be/uTE-jHVIKJU?t=26m39s .


RADAR - Kammhuber Line - German night air defense system
The Kammhuber Line was the Allied name given to the German night air defense system established in July 1940 by Colonel Josef Kammhuber. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fighter. Each sector would direct the night fighter into visual range with target bombers.
.........
When Germany organised its air defences into the Kammhuber Line, it was realised by the British (Bomber Command's Operational Research Section (BC-ORS)) that if the RAF bombers were to fly in a bomber stream they could overwhelm the night fighters who flew in individual cells directed to their targets by ground controllers. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses.

British intelligence soon discovered the nature of the Kammhuber Line and started studying ways to defeat it. At the time RAF Bomber Command sent in their planes one at a time to force the defenses to be spread as far apart as possible, meaning that any one aircraft had to deal with little concentrated flak. This also meant the Himmelbett centres were only dealing with perhaps one or two planes at a time, making their job much easier.

At the urging of R.V. Jones, Bomber Command reorganized their attacks into streams of bombers – the so-called Bomber stream, carefully positioned so the stream flew down the middle of a single cell. Data provided to the British scientists allowed them to calculate that the bomber stream would overwhelm the six potential interceptions per hour that the German "Tame Boar" (Zahme Sau) night fighters could manage in a Himmelbett zone. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses. The introduction of Gee radio navigation in 1942 allowed the RAF bombers to fly by a common route and at the same speed to and from the target, each aircraft being allotted a height band and a time slot in a bomber stream to minimize the risk of collision. The first use of the bomber stream was the first 1,000 bomber raid against Cologne on the night of 30/31 May 1942. This tactic was extremely effective, leading to fighting between Kammhuber and Erhard Milch, his boss.

Although the success rate of the Line dropped, the network of radars and plotting stations continued to prove their worth. Now when a raid started, night fighters from any base within range were directed into the stream, where it was hoped they would be able to find aircraft with their radar. At the same time a massive building program started to add hundreds of Würzburgs to the system, although the infrastructure needed was extensive. The boxes were initially the radius of the Würzburg radars, about 22 miles, but more powerful radar later on made the boxes up to 100 miles across. Eventually, the line of boxes was several deep, especially around larger towns and the Ruhr valley. Once again the system started to score increasing successes against the British raids.

The British were ready for this development, and as soon as the rates started to improve – for the Germans – they introduced "Window". Dropping strips of foil from a number of "lead" bombers, the German radar operators saw what appeared to be a stream entering their box, each packet of chaff appearing to be a bomber on their displays. Night fighters were then sent to attack this stream, only to find empty space. Just as the fighters reached the false stream, the "real" stream appeared hundreds of miles away, too far to be attacked. The first time this was used was during Operation Gomorrah (a week-long bombing campaign against Hamburg) and proved spectacularly effective. The German radar operators eventually learned to spot the lead bombers at the edge of the windowing, making it less effective. The British had held back from introducing Window for over a year lest the technique be adopted by the Germans and used against British cities.

A more sophisticated method for blinding the German radar was "Mandrel", a jamming signal broadcast from aircraft accompanying the bomber stream or later certain bombers themselves. This progressed into jamming techniques against individual German radar types and spoofing radars to see bomber streams that weren't there. The British also attacked the communications between ground stations and fighters, with Operation Corona, broadcasting false directions in authentic accents over the radio.

One other element was long-range nightfighters operating against the German nightfighters, using a system called "Serrate" to home in on the German nightfighter radar signals. At least three squadrons equipped with Bristol Beaufighter and de Havilland Mosquito were part of No. 100 Group RAF supporting Bomber Command with electronic countermeasures.

https://en.wikipedia.org/wiki/Operations_research
.......
The Line was very effective at first, but was soon rendered useless by a simple change in tactics. The RAF directed all of its bombers to fly in a single stream, overwhelming the sectors, who could only intercept a single aircraft at a time. This led to a dramatic drop in interception rates compared to the raid size. The Line was eventually turned into a radar network, and the night fighters improved with their own radar sets to allow them to hunt on their own.
https://en.wikipedia.org/wiki/Kammhuber_Line

RDF – Plane Safety ‘38

Battle Stations - Radar - Documentary + Rare Bonus Footage
https://www.youtube.com/watch?v=NRvcLNLe3VU
Under The Radar - Radar Technological Evolution
https://www.youtube.com/watch?v=BSajdavR6Yw

Chain Home:

Early Radar Memories .
http://spitfiresite.com/2010/04/early-radar-memories.html
Stories of the Battle of Britain 1940 – Chain Home .
http://spitfiresite.com/2010/08/stories-of-the-battle-of-britain-1940-chain-home.html
“The Spies Who Lost the Battle of Britain” .
http://spitfiresite.com/2010/11/the-spies-who-lost-the-battle-of-britain.html
Aboukir’s High-Altitude Spitfire .
http://spitfiresite.com/2010/04/aboukirs-high-altitude-spitfire.html
http://spitfiresite.com/2010/04/deflating-british-radar-myths-of-world-war-ii.html

Filter Room
http://www.telegraph.co.uk/history/battle-of-britain/11865303/The-Battle-of-Britain-as-it-happened-on-September-15-1940-live.html .

Boffins Beat Belligerents >> .
RAF Uxbridge - WW2 command centre > .

RDF – Plane Safety ‘38 > .

RDF - New Forest
New Forest, WW2 ..

Early Radar Memories
http://spitfiresite.com/2010/04/early-radar-memories.html
Stories of the Battle of Britain 1940 – Chain Home
http://spitfiresite.com/2010/08/stories-of-the-battle-of-britain-1940-chain-home.html
“The Spies Who Lost the Battle of Britain”
http://spitfiresite.com/2010/11/the-spies-who-lost-the-battle-of-britain.html
Aboukir’s High-Altitude Spitfire
http://spitfiresite.com/2010/04/aboukirs-high-altitude-spitfire.html


http://spitfiresite.com/2010/04/deflating-british-radar-myths-of-world-war-ii.html




RAF Bawdsey > .

1940s: Radar, RAF High Speed Launch (HSL), AFS, 1941 Jowett pump, Austin 12 taxi, Austin K Fire Truck, WLA & David Brown VAK1 tractor, cavity magnetron & H2S, Daimler Scout Car (Dingo), Bren Gun, gas turbine = Whittle jet engine, Gloster Pioneer & Meteor, ejector seat, Aston Martin DB1 & DB2 & DBR1

https://www.youtube.com/user/EnginePorn/playlists?view=1&shelf_id=0&sort=dd .

Of zoos and fire-fighting, today and in wartime
https://web.archive.org/web/20110902160428/http://worldwarzoogardener1939.wordpress.com/2011/03/22/of-zoos-and-fire-fighting-today-and-in-wartime/

Britain's greatest machines - 1940s > .

https://www.youtube.com/watch?v=eWSMJFeBfj4&list=PLrWZd-gHTah5CuJVlQgNFmk5jeh0-7mNx
at No comments:
Labels: , , , , , ,

Saturday, August 24, 2019

Filter Room - Fighter Command

Bentley Priory & Fighter Command > .
Battle Of Britain: Hugh "Stuffy" Dowding - The Man Who Saved A Nation - War > .
How RAF Prepared For Luftwaffe's Offensive | Battle Of Britain | Timeline > .  


Filter Room - Eileen Younghusband > .
Boffins Beat Belligerents - tb >> .
40-8-13 Adlertag > . Fighter Command infighting - Trafford Leigh-Mallory vs Dowding, Park > .
Big Ego versus Dowding; nightfighters > .

Filter Room
http://www.telegraph.co.uk/history/battle-of-britain/11865303/The-Battle-of-Britain-as-it-happened-on-September-15-1940-live.html . 

at No comments:
Labels: , , , , , , ,

Wednesday, August 14, 2019

Operations Research

..
Operational Research 'ORigin Story' - OR Society > .



Operations research, or operational research (OR) in British usage, is a discipline that deals with the application of advanced analytical methods to help make better decisions. Further, the term operational analysis is used in the British (and some British Commonwealth) military as an intrinsic part of capability development, management and assurance. In particular, operational analysis forms part of the Combined Operational Effectiveness and Investment Appraisals, which support British defense capability acquisition decision-making.

It is often considered to be a sub-field of applied mathematics.The terms management science and decision science are sometimes used as synonyms.

Employing techniques from other mathematical sciences, such as mathematical modeling, statistical analysis, and mathematical optimization, operations research arrives at optimal or near-optimal solutions to complex decision-making problems. Because of its emphasis on human-technology interaction and because of its focus on practical applications, operations research has overlap with other disciplines, notably industrial engineering and operations management, and draws on psychology and organization science. Operations research is often concerned with determining the extreme values of some real-world objective: the maximum (of profit, performance, or yield) or minimum (of loss, risk, or cost). Originating in military efforts before World War II, its techniques have grown to concern problems in a variety of industries.
....
Beginning in the 20th century, study of inventory management could be considered the origin of modern operations research with economic order quantity developed by Ford W. Harris in 1913. Operational research may have originated in the efforts of military planners during World War I (convoy theory and Lanchester's laws). Percy Bridgman brought operational research to bear on problems in physics in the 1920s and would later attempt to extend these to the social sciences.

Modern operational research originated at the Bawdsey Research Station in the UK in 1937 and was the result of an initiative of the station's superintendent, A. P. Rowe. Rowe conceived the idea as a means to analyse and improve the working of the UK's early warning radar system, Chain Home (CH). Initially, he analysed the operating of the radar equipment and its communication networks, expanding later to include the operating personnel's behaviour. This revealed unappreciated limitations of the CH network and allowed remedial action to be taken.
.....
In the World War II era, operational research was defined as "a scientific method of providing executive departments with a quantitative basis for decisions regarding the operations under their control". Other names for it included operational analysis (UK Ministry of Defence from 1962) and quantitative management.

During the Second World War close to 1,000 men and women in Britain were engaged in operational research. About 200 operational research scientists worked for the British Army.

Patrick Blackett worked for several different organizations during the war. Early in the war while working for the Royal Aircraft Establishment (RAE) he set up a team known as the "Circus" which helped to reduce the number of anti-aircraft artillery rounds needed to shoot down an enemy aircraft from an average of over 20,000 at the start of the Battle of Britain to 4,000 in 1941.

In 1941, Blackett moved from the RAE to the Navy, after first working with RAF Coastal Command, in 1941 and then early in 1942 to the Admiralty. 

Blackett's team at Coastal Command's Operational Research Section (CC-ORS) included two future Nobel prize winners and many other people who went on to be pre-eminent in their fields. They undertook a number of crucial analyses that aided the war effort. Britain introduced the convoy system to reduce shipping losses, but while the principle of using warships to accompany merchant ships was generally accepted, it was unclear whether it was better for convoys to be small or large. Convoys travel at the speed of the slowest member, so small convoys can travel faster. It was also argued that small convoys would be harder for German U-boats to detect. On the other hand, large convoys could deploy more warships against an attacker. Blackett's staff showed that the losses suffered by convoys depended largely on the number of escort vessels present, rather than the size of the convoy. Their conclusion was that a few large convoys are more defensible than many small ones.

While performing an analysis of the methods used by RAF Coastal Command to hunt and destroy submarines, one of the analysts asked what colour the aircraft were. As most of them were from Bomber Command they were painted black for night-time operations. At the suggestion of CC-ORS a test was run to see if that was the best colour to camouflage the aircraft for daytime operations in the grey North Atlantic skies. Tests showed that aircraft painted white were on average not spotted until they were 20% closer than those painted black. This change indicated that 30% more submarines would be attacked and sunk for the same number of sightings. As a result of these findings Coastal Command changed their aircraft to using white undersurfaces.

Other work by the CC-ORS indicated that on average if the trigger depth of aerial-delivered depth charges (DCs) were changed from 100 feet to 25 feet, the kill ratios would go up. The reason was that if a U-boat saw an aircraft only shortly before it arrived over the target then at 100 feet the charges would do no damage (because the U-boat wouldn't have had time to descend as far as 100 feet), and if it saw the aircraft a long way from the target it had time to alter course under water so the chances of it being within the 20-foot kill zone of the charges was small. It was more efficient to attack those submarines close to the surface when the targets' locations were better known than to attempt their destruction at greater depths when their positions could only be guessed. Before the change of settings from 100 feet to 25 feet, 1% of submerged U-boats were sunk and 14% damaged. After the change, 7% were sunk and 11% damaged. (If submarines were caught on the surface, even if attacked shortly after submerging, the numbers rose to 11% sunk and 15% damaged). Blackett observed "there can be few cases where such a great operational gain had been obtained by such a small and simple change of tactics".


Map of Kammhuber Line
Bomber Command's Operational Research Section (BC-ORS), analyzed a report of a survey carried out by RAF Bomber Command. For the survey, Bomber Command inspected all bombers returning from bombing raids over Germany over a particular period. All damage inflicted by German air defences was noted and the recommendation was given that armour be added in the most heavily damaged areas. This recommendation was not adopted because the fact that the aircraft returned with these areas damaged indicated these areas were not vital, and adding armour to non-vital areas where damage is acceptable negatively affects aircraft performance. Their suggestion to remove some of the crew so that an aircraft loss would result in fewer personnel losses, was also rejected by RAF command. Blackett's team made the logical recommendation that the armour be placed in the areas which were completely untouched by damage in the bombers which returned. They reasoned that the survey was biased, since it only included aircraft that returned to Britain. The untouched areas of returning aircraft were probably vital areas, which, if hit, would result in the loss of the aircraft. This story has been disputed, with a similar damage assessment study completed in the US by the Statistical Research Group at Columbia University and was the result of work done by Abraham Wald.

When Germany organized its air defences into the Kammhuber Line, it was realized by the British that if the RAF bombers were to fly in a bomber stream they could overwhelm the night fighters who flew in individual cells directed to their targets by ground controllers. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimize RAF losses.

The "exchange rate" ratio of output to input was a characteristic feature of operational research. By comparing the number of flying hours put in by Allied aircraft to the number of U-boat sightings in a given area, it was possible to redistribute aircraft to more productive patrol areas. Comparison of exchange rates established "effectiveness ratios" useful in planning. The ratio of 60 mines laid per ship sunk was common to several campaigns: German mines in British ports, British mines on German routes, and United States mines in Japanese routes.

Operational research doubled the on-target bomb rate of B-29s bombing Japan from the Marianas Islands by increasing the training ratio from 4 to 10 percent of flying hours; revealed that wolf-packs of three United States submarines were the most effective number to enable all members of the pack to engage targets discovered on their individual patrol stations; revealed that glossy enamel paint was more effective camouflage for night fighters than traditional dull camouflage paint finish, and the smooth paint finish increased airspeed by reducing skin friction.

On land, the operational research sections of the Army Operational Research Group (AORG) of the Ministry of Supply (MoS) were landed in Normandy in 1944, and they followed British forces in the advance across Europe. They analyzed, among other topics, the effectiveness of artillery, aerial bombing and anti-tank shooting.

at No comments:
Labels: , , , , , , , , , , , ,
Subscribe to: Posts (Atom)

sī vīs pācem, parā bellum

igitur quī dēsīderat pācem praeparet bellum    therefore, he who desires peace, let him prepare for war sī vīs pācem, parā bellum if you wan...

  • >>>
    >>> Economic >  >>> Geopolitics > >>> Military > >>> Resources > > >> Sociopoli...
  • >>□□ ⧫⧫ ●γ
    >> playlists >>  » >> pages □□ »□ ⧫⧫ section indexes ⧫⧫ ⧫⧫ & ⧫ alphabetic index  ⧫⧫ & ⧫ ● Geographic Entities   ...
  • > > Video Topics > >
    >   > Alliances >  > >  > Authoritarianism >  > > > Civil Wars > > >  > Ċold Ŵar 2 Geopolitics ...