Polar (normal) aspect

Polar aspect is the simplest form of planar map projections. The differences between the three examples that follow are due solely to the position of the light source. The center of the map projection can be either pole, and as a result of this, parallels are represented as concentric circles and all meridians are straight lines with true angles of orientation that converge at the poles. Nearly all maps of Antarctica use a planar map projection.

North polar aspect of a planar projection.

In the Gnomonic projection, parallels are unequally spaced. All great circles are shown as straight lines and therefore indicate the shortest path between two points, so it is commonly used for plotting flight paths. Distances measured from the center are true, but other measured distances are not. For example a straight line represents the shortest path, but measurements of the actual path are not true.

In polar Gnomonic map projections, all meridians are straight lines and parallels are circles.

In the Stereographic and Orthographic projections, parallels are unequally-spaced circles. The Stereographic projection is conformal and therefore commonly used for mapping Antarctica and occasionally Arctic regions. In the Orthographic projection, the center is distortion free, but distortion increases rapidly away from the center so it is used only occasionally.

The polar Stereographic map projection (left) and the polar Orthographic map projection (right).