Three-dimensional current systems in high latitudes are obtained by two independent methods on the basis of magnetic field data obtained from the IMS Alaska meridian chain of observatories. In spite of the totally different principles used, the two methods results in similar large-scale distributions of the ionospheric currents and field-aligned currents, and the estimated values are in reasonable agreement with those observed more directly by radar and satellite techniques. Thus ground-based magnetic field records, together with an advanced computer code for separating the contribution from ionospheric and field-aligned currents, are proven to be a powerful tool in studying the substorm current system, providing a complete set of information on the global distribution of ionospheric currents, electric fields and of field-aligned currents as well as the convection pattern. There are, however, some differences which are mostly intrinsic to each method. These are discussed in detail in terms of advantages and disadvantages of each method.