observation sector
1Sector clock — A Sector clock was a round clock mounted on mahogany used at military airfields and observation posts in the United Kingdom to track the movements of enemy aircaft and control friendly aircraft. History They were originally known as colour change …
2space exploration — Investigation of the universe beyond Earth s atmosphere by means of manned and unmanned spacecraft. Study of the use of rockets for spaceflight began early in the 20th century. Germany s research on rocket propulsion in the 1930s led to… …
3Royal Observer Corps — Ensign Active 1925–1996 Country …
4Ouvrage Hackenberg — Part of Maginot Line Northeast France …
5Ouvrage Fermont — Part of Maginot Line Northeast France …
6Ouvrage Schiesseck — Part of Maginot Line Northeast France …
7Ouvrage Mont Agel — Part of Maginot Line, Alpine Line near Nice …
8Ouvrage La Ferté — Part of Maginot Line Northeast France …
9Ouvrage Sainte-Agnès — Part of Maginot Line, Alpine Line Sainte Agnès, Alpes Maritimes …
10Ouvrage Kerfent — Part of Maginot Line Northeast France …
