Direct density estimation using muon radiography

Muography or muon radiography estimates the density distribution of natural or anthropic structures by measuring the traversing flux of atmospheric muons. Muography has been implemented to image volcanoes, glaciers, tunnels, line-shores, pyramids, and dams. The mass variation of the structure is deduced by the ratio between the open-sky muon flux and the target traversing flux, resulting in a relative measurement of the density. We present a novel method for directly measuring the average density of the target. The methodology uses known muography variables such as open-sky and traversing muon flux, incident zenith angle, and muon path length. We validated the method with muography-simulated data from iron, aluminum, standard rock and water phantoms, as well as real data from the Khufu pyramid, the Eiger Glacier, and the Canfranc Underground Laboratory.