Geocart Projections

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Cahill-Concialdi bat

Description

World projected conformally onto a variation of Cahill’s butterfly arrangement.

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

Distortion

No distortion at the centroid of each face. Maximum distortion at the corners.

Origin

Bernard J.S. Cahill produced his butterfly arrangement in 1909 and promoted it thereafter. He succeeded in having Oscar S. Adams develop the mathematics for a conformal version, which he published in 1929. L.P. Lee greatly expanded upon and regularized the mathematics in 1976. Luca Concialdi developed this variant of the butterfly arrangement in 2015.

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