{"id":14233,"date":"2025-06-03T16:19:18","date_gmt":"2025-06-03T10:49:18","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=14233"},"modified":"2026-07-26T10:15:41","modified_gmt":"2026-07-26T04:45:41","slug":"oblique-mercator-projection","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/oblique-mercator-projection\/","title":{"rendered":"Oblique Mercator Projection"},"content":{"rendered":"<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g16-oblique-mercator-projection-1.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h2>Oblique Mercator Projection<\/h2>\n<p>The Oblique Mercator Projection is a cylindrical projection where the cylinder is placed at an angle to the Earth&#8217;s axis. It is used for mapping regions that extend diagonally or along a great-circle route. It provides accurate representation of direction and shape along the chosen oblique path.<\/p>\n<h3>Introduction to the Oblique Mercator Projection<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g16-oblique-mercator-projection-2.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>An <strong>oblique great circle<\/strong>, known as the <strong>datum great circle<\/strong> or <strong>false equator<\/strong>, is used as the line of tangency instead of the equator.<\/li>\n<li>The Oblique Mercator projection is particularly useful for flights following a specified great circle route.<\/li>\n<li>Scale remains within an error of <strong>1%<\/strong> for approximately <strong>480 NM<\/strong> on either side of the datum great circle.<\/li>\n<\/ul>\n<h3>Scale Expansion in an Oblique Mercator Projection<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g16-oblique-mercator-projection-3.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Scale expansion is proportional to the <strong>secant of the angular distance<\/strong> from the datum great circle.<\/li>\n<li>The Oblique Mercator is an <strong>orthomorphic (conformal)<\/strong> projection.<\/li>\n<li>Scale expands equally in all directions around any point.<\/li>\n<li>Meridians and parallels intersect at <strong>right angles<\/strong>.<\/li>\n<\/ul>\n<h3>Properties of the Oblique Mercator Projection<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g16-oblique-mercator-projection-4.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Meridians and parallels are represented as <strong>complex curves<\/strong>.<\/li>\n<li>They intersect each other at <strong>right angles<\/strong>, preserving angles and bearings.<\/li>\n<li>The projection is orthomorphic because it satisfies the two conditions for conformality:<\/li>\n<ul>\n<li>Equal scale expansion in all directions.<\/li>\n<li>Meridians and parallels intersect at right angles.<\/li>\n<\/ul>\n<\/ul>\n<h3>Chart Convergence in an Oblique Mercator Projection<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g16-oblique-mercator-projection-5.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Chart convergence is equal to Earth convergence only at three locations:<\/li>\n<ul>\n<li>The poles.<\/li>\n<li>The equator.<\/li>\n<li>The datum great circle (false equator).<\/li>\n<\/ul>\n<li>Elsewhere, chart convergence differs from Earth convergence.<\/li>\n<\/ul>\n<h3>Great Circles and Rhumb Lines<\/h3>\n<ul>\n<li>Most <strong>great circles<\/strong> and <strong>rhumb lines<\/strong> are represented as complex curves.<\/li>\n<li>The <strong>datum great circle (false equator)<\/strong>, being the line of tangency, is represented as a straight line.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Oblique Mercator Projection The Oblique Mercator Projection is a cylindrical projection where the cylinder is placed at an angle to the Earth&#8217;s axis. It is used for mapping regions that extend diagonally or along a great-circle route. It provides accurate representation of direction and shape along the chosen oblique path. Introduction to the Oblique Mercator Projection An oblique great circle, known as the datum great circle or false equator, is used as the line of tangency instead of the equator. The Oblique Mercator projection is particularly useful for flights following&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"disable_featured_image":false,"footnotes":""},"categories":[324],"tags":[],"class_list":["post-14233","post","type-post","status-publish","format-standard","hentry","category-cpl-atpl-general-navigation"],"_links":{"self":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14233","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/comments?post=14233"}],"version-history":[{"count":1,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14233\/revisions"}],"predecessor-version":[{"id":16634,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14233\/revisions\/16634"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=14233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=14233"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=14233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}