{"id":14239,"date":"2025-06-03T16:20:35","date_gmt":"2025-06-03T10:50:35","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=14239"},"modified":"2025-06-14T07:04:27","modified_gmt":"2025-06-14T01:34:27","slug":"polar-steriographic-projection","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/polar-steriographic-projection\/","title":{"rendered":"Polar Steriographic Projection"},"content":{"rendered":"\n<h2>Polar Stereographic Projection<\/h2>\n\n\n\n<h3>Azimuthal Projections<\/h3>\n\n\n\n<ul><li>Azimuthal projections are obtained by projection on a horizontal or flat sheet of paper<\/li><li>Since the paper is kept flat the projection forms a circular chart<\/li><li>The reduced earth touches the paper at the pole called point of tangency<\/li><li>Scale is correct only at the pole and expands away from the poles<\/li><\/ul>\n\n\n\n<h3>Scale Expansion of Azimuthal Projections<\/h3>\n\n\n\n<ul><li>Scale expansion is constant in all directions making the projection orthomorphic<\/li><li>Latitudes are concentric circles and longitudes are radial straight lines from the poles<\/li><li>Meridians and parallels intersect at right angles making them easy to plot<\/li><\/ul>\n\n\n\n<h3>Polar Stereographic Projection<\/h3>\n\n\n\n<ul><li>Polar stereographic is a Perspective Orthomorphic Projection<\/li><li>PSP is an Azimuthal projection as the paper is flat<\/li><li>Unlike other projections, light source is placed on the opposite pole<\/li><li>PSP is orthomorphic since the scale expansion is constant in all directions<\/li><li>Meridians are radial straight lines and parallels are concentric circles<\/li><li>Meridians and parallels cut at right angles<\/li><\/ul>\n\n\n\n<h3>Scale Expansion in Polar Stereographic Projection<\/h3>\n\n\n\n<ul><li>Scale is correct at the pole of the projection as it is the point of origin<\/li><li>Scale expands at all other latitudes as a factor of the co-latitude<\/li><li>Co-latitude is angle measured from pole (90 \u00e2\u20ac\u201c latitude)<\/li><li>Scale expansion of Polar Stereographic is given by a formula<\/li><li>Scale Expansion = Sec\u00c2\u00b2 ( \u00c2\u00bd Co-latitude)<\/li><\/ul>\n\n\n\n<h3>Uses of Polar Stereographic<\/h3>\n\n\n\n<ul><li>Polar stereographic is used for flying polar routes as grid charts and as a planning chart for a hemisphere<\/li><li>Scale expansion is within 1% from 90 to 78 degrees North or South<\/li><li>Scale expansion is within 3 % from 78 to 70 degrees North or South<\/li><li>Therefore, the projection can be considered as constant scale plotting chart above 78 degrees North and South<\/li><li>PSP can be used as planning charts from poles to 78 degrees<\/li><li>Shapes are correct at the pole and gets distorted at other latitudes<\/li><\/ul>\n\n\n\n<h3>Chart Convergence<\/h3>\n\n\n\n<ul><li>Chart convergence or cone constant is 1 or maximum which is correct only at the poles<\/li><li>Chart convergence is more than earth convergence at all other latitudes<\/li><li>Track angle of a great circle changes by amount of chart convergence<\/li><li>Change in great circle track on this projection would be equal to the change of longitude<\/li><\/ul>\n\n\n\n<h3>Great Circles and Rhumb Lines<\/h3>\n\n\n\n<ul><li>Great circles are concave to the pole which is the point of origin and Rhumb lines are concave to the pole<\/li><li>Meridians are straight lines although they are also rhumb lines<\/li><li>Above 70 degree North and South latitudes, a straight line can be considered to be great circle<\/li><\/ul>\n\n\n\n<h2>Best of luck<\/h2>\n","protected":false},"excerpt":{"rendered":"<p>Polar Stereographic Projection Azimuthal Projections Azimuthal projections are obtained by projection on a horizontal or flat sheet of paper Since the paper is kept flat the projection forms a circular chart The reduced earth touches the paper at the pole called point of tangency Scale is correct only at the pole and expands away from the poles Scale Expansion of Azimuthal Projections Scale expansion is constant in all directions making the projection orthomorphic Latitudes are concentric circles and longitudes are radial straight lines from the poles Meridians and parallels intersect&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},"categories":[324],"tags":[],"_links":{"self":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14239"}],"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=14239"}],"version-history":[{"count":0,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/14239\/revisions"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=14239"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=14239"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=14239"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}