In 1926 and 1932 already shots had been taken from the air to assist excavations near Laren and in the province of Groningen ; just before the second World War, Von Frijtag Drabbe had made use of vertical air photographs for archaeological research. Flights continued after the war on a modest scale, owing to financial and practical constraints. Recently, Amsterdam University volunteered to contribute to the conservation of archaeological sites through a programme of aerial survey aimed at :

1°) - Overseeing archaeological sites, protected or not ;

2°) - Identifying and localising potential sites, prior to possible legal protection ;

3°) - Mapping sites and monuments.