Aspects and embodiments are generally directed to magnetic field detector systems and methods. In one example, a magnetic field detector system includes a proof-mass including a magnetic dipole source, a plurality of supports, each individual support of the plurality supports being coupled to the proof-mass, a plurality of sensors, each individual sensor of the plurality of sensors positioned to measure a resonant frequency of a corresponding support of the plurality of supports, and a controller coupled to each individual sensor of the plurality of sensors, the controller configured to measure a characteristic of a magnetic field imparted on the proof-mass based on at least a first resonant frequency of the measured resonant frequencies.