engleski

Standard Parallels of Equidistant Conic Projections on Old Maps

In previous research, we proved that meridians are straight lines and parallels are arcs of concentric circles on the map Nuova carta geografica dello Stato Ecclesiastico by J. R. Bošković and Ch. Maire published in 1755. We also proved the map was produced in a nor-mal aspect conic projection equidistant along meridians. In order to know the details of the map projection, we need to determine its parameters and standard parallels. This paper describes the determination of standard parallels of the normal aspect conic pro-jection equidistant along meridians. We propose a procedure for determining projection pa-rameters of an old map, especially its standard parallels, if the radius of the sphere the map was produced in is unknown. Constant C is introduced as a ratio of constant K and sphere radius R, which are unknown. The procedure is illustrated on the example of the map Nuova carta geografica dello Stato Ecclesiastico. The area represented on the map Nuova carta geografica dello Stato Ecclesiastico stretches from about 41°20'N to 45°00'N. In order to test which standard parallels could be selected for the map, we calculated them for the Kirilov and De l'Isle projectiona, the Murdoch I and III projections and the Euler projection. By applying formulas of these map projections, we calculated theoretical rectangular coordinates of the graticule and compared them with co-ordinates of the graticule read from the map.

map projections ; equidistant conic projection ; Kirilov ; De l'Isle ; Murdoch ; Euler ; Nuova carta geografica dello Stato Ecclesiastico

nije evidentirano