Associations with other Armies commenced during the First World War and for more than 50 years after the Second World War the Corps participated in mapping, charting and geodesy projects for standardisation and interoperability with major allies including Canada, New Zealand, United Kingdom and United States. From the 1960s, the Corps participated in cooperative and collaborative geodetic satellite programs with the United States, firstly astro-triangulation of passive satellites Echo and Pageos being observed with Wild BC4 cameras at Thursday Island in Queensland, Narrabri in New South Wales, Perth in Western Australia and Cocos Island, a TRANET fixed station at Smithfield in South Australia in the global network observing US Navy Navigation Satellites (TRANSIT) from 1976 to 1993 and the first observations of US Global Positioning System (GPS) satellites in Australia, at Smithfield, during the development and early operational phases of the system from 1981 to 1994. The Corps managed bi-lateral Defence and Army map exchange arrangements with major allies and regional nations. Personnel exchange programs included Canada, United Kingdom and United States.