Comparison of noise levels of different magnetometer types and space environments

The plasma environment around Earth is divided into several distinct regions with vastly different characteristics of the magnetic field. For example, inside the magnetosphere the magnetic field can reach tens of thousands of nanotesla. In the magnetosheath between Earth’s magnetosphere and the bow shock, the magnetic field is lower, but significantly more turbulent. In the solar wind outside Earth’s magnetic influence, magnetic fields are low and less fluctuating. Magnetic fields in space have typically been measured with fluxgate magnetometers on spacecraft. In recent years, various magnetometer types have been discussed and/or flown, i.e. optically pumped magnetometers or anisotropic magnetoresistive magnetometers. We discuss and compare noise level performances of diverse magnetometer types and contrast them with the requirements needed to accurately observe the magnetic field and distinct plasma phenomena therein in particular regions of space for scientific research.