ROYAL AIR FORCE RADAR, 1939-145. (CH 15331) Chain Home: Flight Officer P M Wright supervises (right) as Sergeant K F Sperrin and WAAF operators Joan Lancaster, Elaine Miley, Gwen Arnold and Joyce Hollyoak work on the plotting map in the Receiver Room at Bawdsey CH, Suffolk. Copyright: © IWM. Original Source: http://www.iwm.org.uk/collections/item/object/205210716