{"id":14241,"date":"2025-06-03T16:21:05","date_gmt":"2025-06-03T10:51:05","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=14241"},"modified":"2026-07-26T10:17:13","modified_gmt":"2026-07-26T04:47:13","slug":"plotting-lamberts-mercator","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/plotting-lamberts-mercator\/","title":{"rendered":"Lamberts and Mercator Plotting"},"content":{"rendered":"<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-1.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h2>Plotting on Charts &#8211; Lambert vs Mercator<\/h2>\n<p>Lambert Projection maintains accurate angles and is suitable for long-distance flight planning. Mercator Projection preserves direction and is mainly used for navigation over equatorial regions.<\/p>\n<h3>Lambert&#8217;s Plotting \u2013 Find Magnetic Bearing<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-2.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Convert relative bearings to magnetic bearings.<\/li>\n<li><strong>Magnetic Bearing = Relative Bearing + Magnetic Heading<\/strong><\/li>\n<li>Subtract <strong>360\u00b0<\/strong> if the value exceeds <strong>360\u00b0<\/strong>.<\/li>\n<li>Convert magnetic bearings <strong>to<\/strong> the station into magnetic bearings <strong>from<\/strong> the station.<\/li>\n<li>Convert <strong>QDM<\/strong> to <strong>QDR<\/strong>.<\/li>\n<li>Add or subtract <strong>180\u00b0<\/strong>.<\/li>\n<\/ul>\n<h3>Lambert&#8217;s Plotting \u2013 Find True Bearing<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-3.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h4>Relative Bearing to True Bearing Conversion<\/h4>\n<ul>\n<li><strong>True Bearing = Relative Bearing + True Heading<\/strong><\/li>\n<li>Subtract <strong>360\u00b0<\/strong> if the value exceeds <strong>360\u00b0<\/strong>.<\/li>\n<\/ul>\n<h3>True Bearing from ADF and VOR<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-4.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>If the bearing is measured at the ground station (e.g., <strong>VOR<\/strong>):\n<ul>\n<li>Apply the station variation to the magnetic bearing to obtain the true bearing.<\/li>\n<\/ul>\n<\/li>\n<li>If the bearing is measured at the aircraft (e.g., <strong>ADF<\/strong>):\n<ul>\n<li>Apply the aircraft variation to the magnetic bearing to obtain the true bearing.<\/li>\n<li>Find the reciprocal bearing from the station.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Lambert&#8217;s Plotting \u2013 Apply Chart Convergence<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-5.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Obtain the bearing to plot by applying chart convergence.<\/li>\n<li>Plot from the false meridian at the ground station.<\/li>\n<li>Alternatively, calculate the chart convergence and then plot.<\/li>\n<\/ul>\n<h3>Mercator Plotting<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-6.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>The lateral direction of radio signals from <strong>VDF<\/strong>, <strong>VOR<\/strong>, and <strong>NDB<\/strong> follows the great-circle path (the shortest path).<\/li>\n<li>On Mercator charts:\n<ul>\n<li>Rhumb lines are straight lines.<\/li>\n<li>Great circles are curved and concave toward the equator.<\/li>\n<\/ul>\n<\/li>\n<li>Measured great-circle bearings must be converted into rhumb-line directions before plotting on a Mercator chart.<\/li>\n<\/ul>\n<h3>Calculation of Bearing to Plot on Mercator<\/h3>\n<p> <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/general-navigation\/g20-plotting-on-lamberts-and-mercator-7.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Apply the conversion angle (<strong>\u00bd convergence<\/strong>) at the point where the bearing is measured to convert from a <strong>Great Circle (GC)<\/strong> to a <strong>Rhumb Line (RL)<\/strong>.<\/li>\n<li>For <strong>VOR<\/strong> and <strong>VDF<\/strong> (bearings measured at the station):\n<ul>\n<li>Apply the station variation and the conversion angle at the station.<\/li>\n<\/ul>\n<\/li>\n<li>For <strong>ADF<\/strong> and <strong>AWR<\/strong> (bearings measured at the aircraft):\n<ul>\n<li>Apply the aircraft variation and the conversion angle at the aircraft.<\/li>\n<li>Plot the reciprocal bearing from the ground station.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Plotting on Charts &#8211; Lambert vs Mercator Lambert Projection maintains accurate angles and is suitable for long-distance flight planning. Mercator Projection preserves direction and is mainly used for navigation over equatorial regions. Lambert&#8217;s Plotting \u2013 Find Magnetic Bearing Convert relative bearings to magnetic bearings. Magnetic Bearing = Relative Bearing + Magnetic Heading Subtract 360\u00b0 if the value exceeds 360\u00b0. Convert magnetic bearings to the station into magnetic bearings from the station. Convert QDM to QDR. Add or subtract 180\u00b0. Lambert&#8217;s Plotting \u2013 Find True Bearing Relative Bearing to True Bearing&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-14241","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\/14241","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=14241"}],"version-history":[{"count":1,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14241\/revisions"}],"predecessor-version":[{"id":16638,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14241\/revisions\/16638"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=14241"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=14241"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=14241"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}