Magnetometers aboard spacecraft and high-altitude balloons can be used to measure the Earth’s magnetic field, in order to map field fluctuations over the planet. Spacemag-lite is an excellent option for this type of measurement, because its magnetometer head can be separated from its electronics. This allows the head to be positioned away from the spacecraft, thereby minimising the effect of the spacecraft’s signature. Atmospheric balloons can be used for similar measurements. In this case, and depending on operational limits, sensors such as the Mag-13 can also be used. See also Space Weather and GIC