A Review of Methods for Reconstructing the Spatial Structure of the Anomalous Magnetic Field of the Earth in the Vicinity of Geomagnetic Observatories

Complete information on the space-time variability of the Earth’s magnetic field is especially important in the vicinity of geomagnetic observatories. The distribution of sources of anomalies in the Earth’s crust associated with rocks and other geological structures allows a better understanding of the origin of the area and the spatial and temporal peculiarities of the Earth’s magnetic field. The magnetic properties of the geological section are also important for assessing the contribution of geomagnetically induced currents during strong geomagnetic disturbances. Temporal changes in the total values of components of the magnetic induction vector T are recorded by the observatory itself. The next question that arises is what part of the magnetic induction vector T is determined by the normal Earth’s magnetic field T and what part is determined by its anomalous component T. To select the optimal approach to calculating the components of the anomalous magnetic field, we considered the methods for restoring its spatial structure used in the exploration magnetometry. It should be noted that the solution of the problem is based on the algorithms for modelling the equivalent distribution of magnetic sources of an anomalous field. The use of multilevel magnetic surveys allows us to obtain a more correct model of the magnetic field than that based on single-level ground or aeromagnetic survey data.