Geocart Projections

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Cahill conformal butterfly

Description

World projected conformally into an octahedron arranged as a “butterfly”.

Classifications

Conformal
Polyhedral

Graticule

Meridians: Complex curves except for the edges and central meridian of each facet
Parallels: Complex curves except for straight edge at base of each facet

Origin

Bernard J.S. Cahill proposed three versions of the same basic butterfly arrangement, beginning in 1909. This is the conformal version, with mathematics for it developed by Oscar S. Adams ~1929. Cahill touted this version for meteorological purposes.

Description ©2019 Mapthematics LLC.