. His work on electrical pulse-code modulation systems<ref>{{cite patent | country=US| patent number=US2730676A| inventor=Barker RH| title= Electrical Pulse Code Modulation| url=<https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=19530520&DB=&locale=en_EP&CC=GB&NR=691810A&KC=A&ND=4#/ref> and digital transmission methods also contributed to early experiments in encrypted radar signals and the foundations of modern air traffic control systems.
1948 A tracking Display and Data Transmission SRDE Tech Memo RES 113▼
1952 Group Synchronising of Binary Digital Systems
1955 GB706687 (A) Electrical Signal Generating Systems IET
▲1948 A tracking Display and Data Transmission SRDE Tech Memo RES 113
1948 Improvements in or relating to Apparatus for data in Binary Digital Form <ref>{{cite web patent|last1country=Barker US|first1number=RH US2730676A|title=Improvements in or relating to apparatus for the representation of data in a binary digital form |url=https://worldwide.espacenet.com/patent/search/family/010175782/publication/GB650913A?q=pn%3DGB650913A |publisher=European Patents Office |access-date=January 24, 2024 |ref=GB650913A |date=1951}}</ref>
1949 Appendix II to Conversion of Shaft Position to Binary Pulse Code.pdf IETR Ref
