Claude Wavell worked for the Aircraft Operating Company from 1928, when he worked in Brazil as Chief Surveyor on an aerial survey of Rio de Janiero. Wavell joined the Central Interpretation Unit in June 1940 and from January 1941 was dedicated to the interpretation of radar installations and wireless transmitters. From November 1941, Squadron Leader Wavell ran G Section, a specialist team responsible for compiling information about all enemy radar, navigational beams and wireless stations.
A skilled mathematician could take half an hour to determine the height of a mast from its shadow seen on aerial photography. Wavell invented a machine based on spherical trigonometry, the Altazimeter, that provided the results in a few minutes.
Wavell and his section subsequently identified the network of Freya and Wurtzburg radar installations along the coastline of occupied Europe.
This material was gifted to NCAP on Tuesday 29 September 2015 by Mr Christopher and Mrs Marilyn Hartley. After buying a house at 43 Albert Road, Gurnard, Cowes, Isle of Wight, in 2008, one of Mr and Mrs Hartley's sons discovered documents and photographs in their attic. Squadron Leader Claude Wavell lived in a neighbouring property (Leindenhurst, Solent View Road, Gurnard, Cowes) and these documents were clearly once his possession.
After the BBC Operation Crossbow documentary was broadcast in May 2011, the importance of the records was impressed on Mrs Hartley, who contacted NCAP. Communication between her and the NCAP Curator continued intermittently, and resulted in their meeting more than five years later.
