The Polyconic projection is neither an equal-area nor a conformal
projection. Scale is true along each parallel and along the central meridian.
Parallels are arcs of non-concentric circles and the projection is free
of distortion only along the central meridian. The Polyconic projection can be used to represent
small areas on any part of the globe, preserving shapes, areas, distances,
and azimuths in their true relation to the surface of the Earth. Polyconic
projections over large areas usually result in serious errors and exaggeration
of details. The "Polyconic" projection has the following
parameters: