Abstract:
The most significant of the Earth’s magnetic field elements is the geomagnetic declination, which is widely used in geodesy, cartography and their associated navigational systems. The geomagnetic declination is incorporated in the naval navigation maps and is used in the navigation process. It is also a very important factor for aviation where declination data have major importance for every airport (civil or military).
As the geomagnetic field changes with time but maps of the geomagnetic declination are not published annually and are reduced to an epoch in the past (Buchvarov and Cholakov, 1985), it is necessary to define two additional parameters in the maps, needed to determine the value of the geomagnetic declination for a particular moment in the future: 1) estimated value of the annual declination variation and 2) a table with the average diurnal variation of the declination for a given month and hour.