US Patent 10338162 AC vector magnetic anomaly detection with diamond nitrogen vacancies

A system for magnetic anomaly detection is described. The system may include a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers. A controller modulates a first code packet and controls a first magnetic field generator to apply a first time varying magnetic field at the NV diamond material based on the modulated first code packet. The controller modulates a second code packet and control a second magnetic field generator to apply a second time varying magnetic field at the NV diamond material based on the modulated second code packet, wherein the first code packet and the second code packet are binary sequences which have a low cross correlation with each other. The controller determines a magnitude and direction of the magnetic field at the NV diamond material, and determines a magnetic vector anomaly based on the determined magnitude and direction of the magnetic field.