Leonard George Chapman
Encyclopedia
Squadron Leader
Leonard George Chapman (28 March 1910 - 25 July 1975) was an inventor, radio engineer and Royal Air Force
officer.
While serving in the Royal Air Force he invented the 'Chapman Method' in 1937-1938. This method accurately determines the location of an object from the time difference of arrival of a signal (possibly radio echo) emitted from that object to three or more receivers. A method commonly used in civil and military surveillance applications, and also known as Multilateration
. Thus it has been suggested that Chapman be nominated as the father of Multilateration.
Chapman was in charge of installing 5 radar stations as part of the Chain Home
system. Including the Netherbutton station in the parish of Holm
, Orkney Islands, the installation of which Chapman performed while only holding the rank of Corporal.
He had a long and distinguished career holding a variety of commands, rising to the rank of Squadron Leader and receiving a permanent commission.
By 1929 the direction of Leonard Chapman's life's work had begun to form when he attended Flowerdown, the Royal Air Force Electrical and Wireless school for training aircraft apprentices.
Subsequently Chapman attended the Chatham Technical School for 2 years. He was then accepted into the Engineering Department of Woolwich Polytechnic for 3 years, after which he attended the Royal Air Force Electrical and Radio School for 3 years. Finally in 1937 he attended the Ground Radar course under Watson-Watt.
Another option was proposed on the 12th February 1935 by Watson-Watt in a memo entitled Detection and location of aircraft by radio methods sent to the Air Ministry
. This detection and location method known today as radar, combined with a command and control system would act as a Force multiplier by allowing friendly fighters to know the exact location of enemy bombers and converge on them. On the 26th February a successful demonstration of radar was given at Daventry
, Northhamptonshire. By the end of 1935 a system with a detection and location range of 100 km had been established, and plans were made in December to set up five fixed radar stations covering London airspace. One of these stations was to be located on the coast near Orford Ness
, and Bawdsey Manor Research Station
was set up there to become the main centre for all radar research.
). In his resume Chapman states "This was the first system to use pulse techniques and hyperbolic intersections for position finding". This proposal was implemented and evaluated by Sir Edward Fennessey, one of the Bawdsey staff. While Chapman's proposal was ultimately not used in Chain Home, the multilateration technique is now commonly used in civil and military surveillance applications to accurately locate aircraft, vehicles and stationary emitters.
. From 1938-1940 Chapman supervised construction of 5 Chain Home radar stations, including the Netherbutton station in Holm, Orkney Islands.
From 1941-1944 Chapman was a staff member at the Royal Air Force Scottish Headquarters serving as senior installation officer, senior training officer, and operations officer.
system was used in conjunction with intelligence services such as the "Y" Service radio posts, these components formed part of an overall system of integrated air defense system known as the Dowding system. This complex infrastructure of detection, command, and control provided the keystone of the British defence during the Battle of Britain
.
This battle engaged the German Air Force (Luftwaffe
) against the United Kingdom during 1940. The objective of the numerically superior Luftwaffe was to gain air superiority over the Royal Air Force
, so that Operation Sea Lion an amphibious and airborne invasion of Britain could be launched.
The outcome of the battle was a decisive British victory, a crucial turning point in the Second World War.
Chapman became a permanently commissioned officer on the 19th May 1952.
equipment at Winkfield, near Windsor.
Whilst supervising construction of a radar station in Netherbutton, Orkney Islands, Leonard meet his wife to be Jemmima Leamonth, who worked in a local radio shop. They were married on the 23rd June 1940 at Kirkwall, Orkney Islands. Leonard would not even let Jemmima know the secret of radar.
Leonard and Jemmima remained married until Leonard's death in 1975. During their marriage they had a daughter they named Patricia. Patricia assisted Leonard with his work on Satellite Tracking
at Winkfield, near Windsor.
Leonard was the second eldest child of George and Ellen. He had 3 siblings, namely a brother Victor who died young, and two sisters Dora, and Winifred. At Winifred's funeral it was said she worked at Bletchley Park
with Alan Turing
, but sadly no information on her contribution has been officially released.
Squadron Leader
Squadron Leader is a commissioned rank in the Royal Air Force and the air forces of many countries which have historical British influence. It is also sometimes used as the English translation of an equivalent rank in countries which have a non-English air force-specific rank structure. In these...
Leonard George Chapman (28 March 1910 - 25 July 1975) was an inventor, radio engineer and Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
officer.
While serving in the Royal Air Force he invented the 'Chapman Method' in 1937-1938. This method accurately determines the location of an object from the time difference of arrival of a signal (possibly radio echo) emitted from that object to three or more receivers. A method commonly used in civil and military surveillance applications, and also known as Multilateration
Multilateration
Multilateration is a navigation technique based on the measurement of the difference in distance to two or more stations at known locations that broadcast signals at known times. Unlike measurements of absolute distance or angle, measuring the difference in distance results in an infinite number of...
. Thus it has been suggested that Chapman be nominated as the father of Multilateration.
Chapman was in charge of installing 5 radar stations as part of the Chain Home
Chain Home
Chain Home was the codename for the ring of coastal Early Warning radar stations built by the British before and during the Second World War. The system otherwise known as AMES Type 1 consisted of radar fixed on top of a radio tower mast, called a 'station' to provide long-range detection of...
system. Including the Netherbutton station in the parish of Holm
Holm, Mainland Orkney
Holm, pronounced "Ham", is a parish on Mainland, Orkney. It is not to be confused with the many Orkney Islands with "holm" in their name.An adjacent Sound, running between Mainland, and Burray, is also named after Holm. It has since been blocked up by the Churchill Barriers...
, Orkney Islands, the installation of which Chapman performed while only holding the rank of Corporal.
He had a long and distinguished career holding a variety of commands, rising to the rank of Squadron Leader and receiving a permanent commission.
Early life
Leonard Chapman was born on the 28th of March 1910 to father George Chapman and mother Ellen Cole. George Chapman was serving at the time in the Queen's Northamptonshire Regiment.By 1929 the direction of Leonard Chapman's life's work had begun to form when he attended Flowerdown, the Royal Air Force Electrical and Wireless school for training aircraft apprentices.
Subsequently Chapman attended the Chatham Technical School for 2 years. He was then accepted into the Engineering Department of Woolwich Polytechnic for 3 years, after which he attended the Royal Air Force Electrical and Radio School for 3 years. Finally in 1937 he attended the Ground Radar course under Watson-Watt.
Context of Chapman's work
During the late 1920s and the 1930s due to advances in aircraft technology London and other cities were becoming increasingly vulnerable to (theoretical) attack by high altitude aircraft bombers. Such bombers could fly out of reach of ground based anti-aircraft guns. Another defensive option was fighter planes, specifically continual high altitude patrolling of the sky by fighters. But the time required for fighters to gain sufficient altitude to engage high altitude aircraft bombers meant this option of continuous 'standing patrols' would have been too expensive in pilot hours, engine wear and fuel consumption to have been effective.Another option was proposed on the 12th February 1935 by Watson-Watt in a memo entitled Detection and location of aircraft by radio methods sent to the Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
. This detection and location method known today as radar, combined with a command and control system would act as a Force multiplier by allowing friendly fighters to know the exact location of enemy bombers and converge on them. On the 26th February a successful demonstration of radar was given at Daventry
Daventry
Daventry is a market town in Northamptonshire, England, with a population of 22,367 .-Geography:The town is also the administrative centre of the larger Daventry district, which has a population of 71,838. The town is 77 miles north-northwest of London, 13.9 miles west of Northampton and 10.2...
, Northhamptonshire. By the end of 1935 a system with a detection and location range of 100 km had been established, and plans were made in December to set up five fixed radar stations covering London airspace. One of these stations was to be located on the coast near Orford Ness
Orford Ness
Orford Ness is a cuspate foreland shingle spit on the Suffolk coast in Great Britain, linked to the mainland at Aldeburgh and stretching along the coast to Orford and down to North Wier Point, opposite Shingle Street. It is divided from the mainland by the River Alde, and was formed by longshore...
, and Bawdsey Manor Research Station
Telecommunications Research Establishment
The Telecommunications Research Establishment was the main United Kingdom research and development organization for radio navigation, radar, infra-red detection for heat seeking missiles, and related work for the Royal Air Force during World War II and the years that followed. The name was...
was set up there to become the main centre for all radar research.
Development of the Chapman Method including Multilateration
During 1937, Chapman attended the Ground Radar course given by Watson-Watt at Bawdsey Manor. During 1937-1938 he devised and proposed a method for obtaining more precise measurements of target locations using differences in time arrival of a signal which became known as the 'Chapman Method' (also known as the 'Chapman System' or MultilaterationMultilateration
Multilateration is a navigation technique based on the measurement of the difference in distance to two or more stations at known locations that broadcast signals at known times. Unlike measurements of absolute distance or angle, measuring the difference in distance results in an infinite number of...
). In his resume Chapman states "This was the first system to use pulse techniques and hyperbolic intersections for position finding". This proposal was implemented and evaluated by Sir Edward Fennessey, one of the Bawdsey staff. While Chapman's proposal was ultimately not used in Chain Home, the multilateration technique is now commonly used in civil and military surveillance applications to accurately locate aircraft, vehicles and stationary emitters.
Chain Home contributions
By 1937 three of the five planned radar towers were demonstrably operational and the government gave an order to build additional stations, forming a chain of fixed radar towers known as Chain HomeChain Home
Chain Home was the codename for the ring of coastal Early Warning radar stations built by the British before and during the Second World War. The system otherwise known as AMES Type 1 consisted of radar fixed on top of a radio tower mast, called a 'station' to provide long-range detection of...
. From 1938-1940 Chapman supervised construction of 5 Chain Home radar stations, including the Netherbutton station in Holm, Orkney Islands.
From 1941-1944 Chapman was a staff member at the Royal Air Force Scottish Headquarters serving as senior installation officer, senior training officer, and operations officer.
Chain Home applied
The Chain HomeChain Home
Chain Home was the codename for the ring of coastal Early Warning radar stations built by the British before and during the Second World War. The system otherwise known as AMES Type 1 consisted of radar fixed on top of a radio tower mast, called a 'station' to provide long-range detection of...
system was used in conjunction with intelligence services such as the "Y" Service radio posts, these components formed part of an overall system of integrated air defense system known as the Dowding system. This complex infrastructure of detection, command, and control provided the keystone of the British defence during the Battle of Britain
Battle of Britain
The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...
.
This battle engaged the German Air Force (Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
) against the United Kingdom during 1940. The objective of the numerically superior Luftwaffe was to gain air superiority over the Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
, so that Operation Sea Lion an amphibious and airborne invasion of Britain could be launched.
The outcome of the battle was a decisive British victory, a crucial turning point in the Second World War.
Post Second World War work
Chapman worked for the Royal Air Force until 1964. From 1944-1953 he was consecutively the commanding officer of a radar convoy unit, the Servicing Wing R.E.U Henlow, RAF Grangemouth, and Skendleby radar station. From 1958-1959 he worked at Scottish Sector Headquarters on radar operations and electronic countermeasures. From 1959-1960 he was the commanding officer of the North German "G" Chain. From 1961-1964 he worked at Fighter Command headquarters on ground radar servicing.Chapman became a permanently commissioned officer on the 19th May 1952.
Work in the private sector
Chapman's work in the private sector included managing airfield radar maintenance at Airwork Services and managing Satellite TrackingSatellite tracker
Satellite tracker or satellite tracking may refer to any of the following:* GPS satellite tracking, a geo-positioning system using GPS satellites* Satellite watching or tracking, a hobby involving tracking human satellites...
equipment at Winkfield, near Windsor.
Personal life
When Leonard Chapman was a school boy his mother died whilst giving birth to his sister Dora. His father, George Chapman, remarried within a year to an Army Nurse, and within 3 years they had a daughter Winifred. George Chapman was a proud Army man successfully becoming a commissioned officer by working his way up from Private to Lieutenant. He did not believe that the relatively recently formed Royal Air Force was a 'real force' that could offer Leonard the same opportunities as the Army. Thus Leonard showed strong independence by attending Flowerdown boys and joining the Royal Air Force.Whilst supervising construction of a radar station in Netherbutton, Orkney Islands, Leonard meet his wife to be Jemmima Leamonth, who worked in a local radio shop. They were married on the 23rd June 1940 at Kirkwall, Orkney Islands. Leonard would not even let Jemmima know the secret of radar.
Leonard and Jemmima remained married until Leonard's death in 1975. During their marriage they had a daughter they named Patricia. Patricia assisted Leonard with his work on Satellite Tracking
Satellite tracker
Satellite tracker or satellite tracking may refer to any of the following:* GPS satellite tracking, a geo-positioning system using GPS satellites* Satellite watching or tracking, a hobby involving tracking human satellites...
at Winkfield, near Windsor.
Leonard was the second eldest child of George and Ellen. He had 3 siblings, namely a brother Victor who died young, and two sisters Dora, and Winifred. At Winifred's funeral it was said she worked at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
with Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
, but sadly no information on her contribution has been officially released.