Geographic coordinate system of 2500 K Magnetic Lineament Map of Iran is unknown and despite of attempts of Committee for Codifying Geological Map Data Model, this problem didn’t solved until preparation of map in GIS area.
So, after digitization of features, for translation of map to correct coordinate, a geographical coordinate system relevant to the map was created and transformed to basal projection system of 1000 K maps. Based on headings of map’s data model, rubbersheet operation of 9 points into correct coordinate was done. But, because of problem in distance between geographical latitudes and longitudes in paper map, some controlling points didn’t have an acceptable match with basal coordinate system. This mismatching distance in the paper map was between –1 to +1 millimeters (in 2500 K Scale) that it subdivides unsystematically in 58 points.
At second step, the operation was done with 52 controlling points. This operation derived a better result for sympathy of features but not at all.
In the next step, the points increased to 92, but deviation and undulating of map did not decreased significantly and some new irregularities were occurred because of points with incorrect coordinate.
Ultimately, the committee selected the 52 points rubbersheet map as the best choice.
Committee for Codifying Geological Map Data Model