Countless generations of people, living for thousands of years on the territory that today is France, built large numbers of structures of varying sizes (houses, graves, various types of buildings) and dug the earth into various constructions (ditches, pits, wells, mines, quarries, etc.). Today, most of these elements are no longer visible on the surface, but their vestiges remain, leveled off in the subsoil — archaeological sites to be located and explored.
This buried national heritage is the object of a systematic inventory on the part of the State in order to ensure that these fragile treasures are safeguarded, preserved, and passed on. More than 300,000 sites can currently be found on the "Archaeological map" drawn up by the Ministry of Culture (via the DRACs, regional (Departmental Offices for Architecture and Heritage, archaeology sub-departments, and the Regional Archaeology Departments within the DRACs for each region). They are described in the PATRIARCHE program, which benefits from the numerous possibilities offered GIS (Global Information System).
It contains every material trace of ancient human presence in the form of objects or structures, already known through the systematic examination of available publications and the various usable sources (archives, maps and drawings, indices drawn up by prospecting on the ground or by electromagnetic detection, etc.).
Aerial prospecting is one of the methods of detecting archaeological sites, and one of the most efficient. It alone can furnish general information for vast areas of land, allowing an inventory of previously unknown vestiges to be established. It makes it possible to intelligently program the archaeological excavations to be undertaken.