engleski

The map projection and accuracy of one Mercator's map

The paper describes research on Mercator’s map 'Sclavonia, Croatia, Bosnia cum Dalmatiae parte'. The map was produced in several editions and shows a great part of present-day Croatia. Zagreb, the capital of Croatia, is shown in two different places on this map, which naturally raises the question of its accuracy. One of the first steps in the research process is to find the mathematical basis, i.e. the projection used to produce the map. The research results showed it was a trapezoidal projection but, according to our knowledge, there are no references as to where appropriate derivations of the projection equations can be found. Derivations of the equations for Mercator’s trapezoidal projection are given based on Mercator’s description shown in our previous paper, being prepared for the International Cartographic Conference in Dresden in 2013. Mercator used this map projection to prepare 'Sclavonia, Croatia, Bosnia cum Dalmatiae parte' and many other maps. Moreover, Mercator’s trapezoidal projection can be generalised to obtain the Collignon, Eckert I and Eckert II projections, as well as the Müffling or polyhedral projection used for topographic maps in Europe and Russia in the first half of the 20th century. During further research, it was necessary to determine the possible differences between the theoretical map projection, as imagined and theoretically set out by Mercator, and the real one, which is incorporated as the basis of the map. Finally, we were able to compare our accuracy estimation results with results obtained using MapAnalyst, software developed at the Institute for Cartography of the Federal Institute of Technology (Eidgenössische Technische Hochschule– ETH) in Zurich.

Mercator; accuracy analysis; trapezoidal projection

nije evidentirano