f The inverse problem for local magnetizations, applied to bomb detection at Schiphol Airport

We developed a method that gives considerable improvements in the interpretation of dense measurements of the magnetic field, at the surface and in boreholes, due to buried objects such as containers with toxic waste or unexploded bombs. The method uses the full data set without averaging procedures. Compared to the large costs involved in digging for deeply buried and often dangerous objects, the extra cost involved in computing the localized magnetization is negligible. The greater reliability of a well designed inverse method will thus easily pay off. We show results of some theoretical investigations and from an actual application at Schiphol airport, where building activity requires detection and dismantling of unexploded WWII bombs at depths up to 15m.