A new Atom Interferometer-Based Gravity Gradiometer developed at Yale University has the potential to outperform existing gravity-sensing technologies while reducing cost and improving reliability. This very precise inertial force sensor will assist submarines in passive navigation in the littoral zone. On land, the gradiometer will assist in the detection of excavated underground structures, such as bunkers and tunnels. The sensor operates from land or air-based platforms. It is especially well-suited to moving vehicles. Commercial applications include geophysical mineral exploration and passive detection of hidden pathways in archaeological studies of pyramids.