The Oblique Mercator Projection is used to show regions along a great circle other than the Equator (Mercator) or a meridian (Transverse Mercator). This kind of map can be made to show as a straight line the shortest distance between any two preselected points along the selected great circle.
Some projections that are derived from the Oblique Mercator projection are:
To convert Oblique Mercator coordinates, the following parameters have to be set: