gnomonic projection

cartography

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Last updated

June 29, 2026

Quick Summary

A gnomonic projection is a type of azimuthal map projection where the Earth's grid is projected from the center of the sphere onto a tangent plane. This method is valuable in cartography because all straight lines on a gnomonic map represent arcs of great circles, which are the shortest distances between two points on a sphere.1

This projection is particularly useful for navigation, especially when used in conjunction with the Mercator projection. While the Mercator projection is excellent for plotting compass bearings, the gnomonic projection helps navigators plot long-distance routes by showing the true great-circle path. Maps using this projection are often referred to as great-circle charts.12

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Map projections
…Earth, the projection is called gnomonic; if from the far side of the Earth’s surface, it is stereographic; if from space, it is called orthographic.
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…Earth, the projection is called gnomonic; if from the far side of the Earth’s surface, it is stereographic; if from space, it is called orthographic.
Read More