The compact, industrial Differential Quantum Gravimeter from iXblue SAS provides accurate underground mapping for near-surface geophysics, civil engineering, and gravity-aided navigation. The sensor can simultaneously measure the absolute values of both gravitational acceleration and its vertical gradient, removing the ambiguity between the determination of the mass of the gravity anomaly and its location. Applications include civil engineering and defense for the detection of underground cavities, mining, prospection, and reservoir management in geothermy.