{"id":5133,"date":"2015-10-23T21:21:00","date_gmt":"2015-10-24T02:21:00","guid":{"rendered":"http:\/\/gisgeography.com\/?p=5133"},"modified":"2025-04-11T04:43:52","modified_gmt":"2025-04-11T09:43:52","slug":"map-projections","status":"publish","type":"post","link":"https:\/\/gisgeography.com\/map-projections\/","title":{"rendered":"How Map Projections Work"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"1100\" height=\"650\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png\" alt=\"goode map projection\" class=\"wp-image-18552\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png 1100w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-300x177.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-678x401.png 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-768x454.png 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-50x30.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-70x40.png 70w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-200x118.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-425x251.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-550x325.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-115x68.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-850x502.png 850w\" sizes=\"auto, (max-width: 1100px) 100vw, 1100px\" \/><\/figure>\n<\/div>\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">What are Map Projections?<\/h2>\n\n\n\n<p>Earth is a big blue marble that&#8217;s the <a href=\"http:\/\/gisgeography.com\/ellipsoid-oblate-spheroid-earth\/\">shape of a sphere<\/a> (or close to it). This is why a globe is the best way to represent the Earth.<\/p>\n\n\n\n<p>But globes are hard to carry in your suitcase and you can only see one side of the globe. On top of that, it&#8217;s hard to measure distances and they&#8217;re just <a href=\"https:\/\/gisgeography.com\/paper-maps\/\">not as convenient as paper maps<\/a>.<\/p>\n\n\n\n<p>This is why we use map projections on globes and flatten them out in two dimensions. But as you&#8217;re about to find out, <a href=\"http:\/\/gisgeography.com\/map-distortion-tissots-indicatrix\/\">you can&#8217;t represent Earth\u2019s surface in two dimensions without distortion<\/a>.<\/p>\n\n\n\n<p>On top of that, all types of map projections have strengths and weaknesses preserving different attributes.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">Peel an Orange and Flatten the Peels<\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"http:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-300x300.png\" alt=\"Map Projection Georeference\" class=\"wp-image-5135\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-300x300.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-150x150.png 150w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-50x50.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-200x200.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-425x425.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-550x550.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-115x115.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference-155x155.png 155w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/05\/Map-Projection-Georeference.png 566w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n<p>Imagine you have an orange. This is your imaginary Earth. When you look at it in any direction, you won&#8217;t be able to see all sides of it. But when you <strong>peel the orange<\/strong>, flatten and stretch it out, you can <strong>begin to see everything<\/strong>.<\/p>\n\n\n\n<p>Similarly, a map projection is a method by which cartographers translate a sphere or globe into a two-dimensional representation. In other words, a map projection systematically <strong>renders a 3D ellipsoid<\/strong> (or spheroid) of Earth to a <strong>2D map surface<\/strong>.<\/p>\n\n\n\n<p>There are multiple ways to represent a sphere on a two-dimensional surface, as you can see in this <a href=\"https:\/\/www.jasondavies.com\/maps\/transition\/\" target=\"_blank\" rel=\"noopener noreferrer\">Map Projection Transition Visualizer<\/a>.<\/p>\n\n\n\n<p>Because you can&#8217;t display 3D surfaces perfectly in two dimensions, distortions always occur. For example, map projections distort distance, direction, scale, and area.<\/p>\n\n\n\n<p>Every projection has strengths and weaknesses. All in all, it is up to the cartographer to determine what projection is most favorable for its purpose.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"550\" height=\"325\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-550x325.png\" alt=\"goode map projection\" class=\"wp-image-18552\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-550x325.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-300x177.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-678x401.png 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-768x454.png 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-50x30.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-70x40.png 70w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-200x118.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-425x251.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-115x68.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-850x502.png 850w, https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png 1100w\" sizes=\"auto, (max-width: 550px) 100vw, 550px\" \/><\/figure>\n<\/div><\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">Developable Surfaces in Map Projections<\/h2>\n\n\n\n<p>As you&#8217;ve already learned, map projections are fundamental tools in cartography that aim to depict the Earth&#8217;s three-dimensional surface on a two-dimensional map.<\/p>\n\n\n\n<p>To achieve this, mapmakers utilize various mathematical techniques to transform the Earth&#8217;s curved surface onto different geometric shapes known as <strong>developable surfaces<\/strong>. For example, these surfaces include cylinders, cones, and planes.<\/p>\n\n\n\n<p>The goal of a developable surface is to <strong>flatten the world<\/strong> in a two-dimensional plane. Each surface is mathematically rendered based on those geometric shapes.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 class=\"wp-block-heading\">Conic Projections<\/h3>\n\n\n\n<p>When you place a cone on the Earth and unwrap it, this results in a <strong>conic projection<\/strong>. For example, the Albers Equal Area Conic and the Lambert Conformal Conic projections are conic projections.<\/p>\n\n\n\n<p>Both of these map projections are well-suited for mapping long east-west regions because distortion is constant along common parallels.<\/p>\n\n\n\n<p>But they struggle at projecting the whole planet. While the area is distorted, the scale is mostly preserved. For <a href=\"http:\/\/gisgeography.com\/conic-projection-lambert-albers-polyconic\/\">conic map projections<\/a>, distance at the bottom of the image suffers with the most distortion.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1925\" height=\"1056\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection.jpg\" alt=\"North America Lambert Conformal Conic Projection\" class=\"wp-image-96697\" style=\"width:700px\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection.jpg 1925w, https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection-300x165.jpg 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection-678x372.jpg 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection-768x421.jpg 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2017\/04\/North-America-Lambert-Conformal-Conic-Projection-1536x843.jpg 1536w\" sizes=\"auto, (max-width: 1925px) 100vw, 1925px\" \/><\/figure>\n<\/div><\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 class=\"wp-block-heading\">Cylindrical Projections<\/h3>\n\n\n\n<p>When you place a cylinder around a globe and unravel it, you get the <strong>cylindrical projection<\/strong>. Strangely enough, you see <a href=\"http:\/\/gisgeography.com\/cylindrical-projection\/\">cylindrical map projections<\/a> like the Mercator and Miller for wall maps even though they inflate the Arctic.<\/p>\n\n\n\n<p>But it makes sense why navigators and even Google Maps use the Mercator projections \u2013 it\u2019s all because of the unique properties of cylinders and north always facing up.<\/p>\n\n\n\n<p>You can place it in a vertical, horizontal, or oblique position such as the <a href=\"http:\/\/gisgeography.com\/state-plane-coordinate-system-spcs\/\">State Plane Coordinate System<\/a>. Each one has its own use in mapping the world.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"678\" height=\"372\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/02\/Miller-Cylindrical-Projection-678x372.jpg\" alt=\"Miller Cylindrical Projection\" class=\"wp-image-96745\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/02\/Miller-Cylindrical-Projection-678x372.jpg 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/02\/Miller-Cylindrical-Projection-300x165.jpg 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/02\/Miller-Cylindrical-Projection-768x421.jpg 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/02\/Miller-Cylindrical-Projection.jpg 1200w\" sizes=\"auto, (max-width: 678px) 100vw, 678px\" \/><\/figure>\n<\/div><\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 class=\"wp-block-heading\">Azimuthal Projections<\/h3>\n\n\n\n<p>These types of projections plot the surface of the Earth using a <strong>flat plane<\/strong>. Similar to light rays radiating from a source following straight lines, those light rays intercept the globe onto a plane at various angles.<\/p>\n\n\n\n<p>The light source can be emitted from different positions developing different <a href=\"http:\/\/gisgeography.com\/azimuthal-projection-orthographic-stereographic-gnomonic\/\">azimuthal map projections<\/a>. For example, gnomonic, stereographic, and orthographic are common azimuthal projections.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"658\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/06\/Stereographic-Projection.jpg\" alt=\"Stereographic Projection\" class=\"wp-image-96729\" style=\"width:650px\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/06\/Stereographic-Projection.jpg 1200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/06\/Stereographic-Projection-300x165.jpg 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/06\/Stereographic-Projection-678x372.jpg 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2016\/06\/Stereographic-Projection-768x421.jpg 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n<\/div><\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">Map Projections and Coordinate Systems<\/h2>\n\n\n\n<p>Remember that with a sphere, we use <a href=\"http:\/\/gisgeography.com\/latitude-longitude-coordinates\/\">latitude and longitude<\/a> to pinpoint our position. This is our geographic coordinate system. For example, New York&#8217;s position is (40.714\u00b0, -74.006\u00b0).<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"550\" height=\"352\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-550x352.png\" alt=\"Latitude, Longitude Coordinate Reference Systems\" class=\"wp-image-7583\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-550x352.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-300x192.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-50x32.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-200x128.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-425x272.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-115x74.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums-242x155.png 242w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Horizontal-Datums.png 620w\" sizes=\"auto, (max-width: 550px) 100vw, 550px\" \/><\/figure>\n<\/div>\n\n\n<p>But when the Earth has a map projection, this means that it has projected coordinates. For example, the <a href=\"https:\/\/gisgeography.com\/utm-universal-transverse-mercator-projection\/\">Universal Transverse Mercator system<\/a> splits the Earth into 60 sections by lines of longitude. If you can imagine you are cutting an orange into 60 wedges, this is how the UTM system works.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"678\" height=\"582\" src=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2019\/04\/UTM-Secant-Tangent-Cylinder-678x582.jpg\" alt=\"UTM Secant Tangent Cylinder\" class=\"wp-image-96475\" style=\"width:350px\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2019\/04\/UTM-Secant-Tangent-Cylinder-678x582.jpg 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2019\/04\/UTM-Secant-Tangent-Cylinder-300x258.jpg 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2019\/04\/UTM-Secant-Tangent-Cylinder.jpg 730w\" sizes=\"auto, (max-width: 678px) 100vw, 678px\" \/><\/figure>\n<\/div>\n\n\n<p>From here, it assigns the <a href=\"https:\/\/gisgeography.com\/central-meridian\/\">central meridian<\/a> a value of <strong>500,000 meters<\/strong>.<\/p>\n\n\n\n<p>The key takeaway is this:<\/p>\n\n\n\n<p>When we locate positions on a sphere, we use <strong>decimal degrees<\/strong>. But when we use map projections, we locate positions in meters or feet.<\/p>\n\n\n\n<p>It uses an equation to transform Earth\u2019s angular geographic coordinates to XY Cartesian coordinates using <a href=\"http:\/\/mathworld.wolfram.com\/DevelopableSurface.html\" target=\"_blank\" rel=\"noopener noreferrer\">developable surfaces<\/a>. A developable surface is a geometric shape that a map projection can be built on.<\/p>\n\n\n\n<p>Actually, some map projections don&#8217;t use developable surfaces at all such as the Goode and Bonne projections.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">Examples of Map Projections<\/h2>\n\n\n\n<p>Throughout human history, people have used map projections for a wide range of uses. Explorers use Mercator maps for <a href=\"http:\/\/gisgeography.com\/rhumb-lines-loxodromes\/\">rhumb lines<\/a> to accurately travel in a constant track direction. Actually, the first known map originated in Greece and perceived the world as cylindrical.<\/p>\n\n\n\n<p>There are <strong>thousands of map projections<\/strong> that are in existence today!<\/p>\n\n\n\n<p>Some map projections are useful for some things and other map projections are good for other things.<\/p>\n\n\n\n<p>Two of the most common map projections used in North America are the Lambert conformal conic and the Transverse Mercator.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 class=\"wp-block-heading\">Lambert Conformal Conic<\/h3>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"187\" src=\"http:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-300x187.png\" alt=\"Lambert Conformal Conic\" class=\"wp-image-7447\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-300x187.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-678x423.png 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-768x479.png 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-50x31.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-200x125.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-425x265.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-550x343.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-115x72.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic-248x155.png 248w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Lambert-Conformal-Conic.png 782w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption class=\"wp-element-caption\">Continental North America: Lambert Conformal Conic<\/figcaption><\/figure>\n<\/div>\n\n\n<p>The Lambert Conformal Conic is derived from a cone intersecting the ellipsoid along two standard parallels. When you &#8220;unroll&#8221; the cone on a flat surface, this becomes the mathematically developed surface.<\/p>\n\n\n\n<p>The most distortion occurs in the north-south directions. In general, distortion increases away from the standard parallels. For example, this map projection severely expands South America.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 class=\"wp-block-heading\">Universal Transverse Mercator<\/h3>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"187\" src=\"http:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-300x187.png\" alt=\"North America: Mercator\" class=\"wp-image-7448\" srcset=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-300x187.png 300w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-678x423.png 678w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-768x479.png 768w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-50x31.png 50w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-200x125.png 200w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-425x265.png 425w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-550x343.png 550w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-115x72.png 115w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America-248x155.png 248w, https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/09\/Mercator-North-America.png 782w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption class=\"wp-element-caption\">Continental North America: Mercator<\/figcaption><\/figure>\n<\/div>\n\n\n<p>The <a href=\"https:\/\/gisgeography.com\/utm-universal-transverse-mercator-projection\/\">Universal Transverse Mercator (UTM) coordinate system<\/a> is a standard set of map projections with a central meridian for each six-degree wide UTM zone. Even though Google Maps used the Mercator projection because it preserves shape decently, and north is always up.<\/p>\n\n\n\n<p>But Mercator map projections are really bad at preserving area. For most of us, the projection is common enough that it looks fine. In reality, Africa is huge on the globe. But Greenland appears to be as large as Africa, even though in reality it is only 1\/14th the size. The Mercator puzzle game illustrates this point.<\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">What is Your Favorite Map Projection?<\/h2>\n\n\n\n<p>Spatial referencing systems (latitude and longitude) are used to locate a feature on the Earth\u2019s spheroid surface. The location of any point on Earth can be defined using latitudes and longitudes. These points are expressed in angular units such as degrees, minutes, and seconds.<\/p>\n\n\n\n<p>Most maps in a GIS are in two-dimensional form. To make use of these maps, you need <a href=\"https:\/\/gisgeography.com\/horizontal-datum\/\">reference systems<\/a> that use a pair of coordinates.<\/p>\n\n\n\n<p>However, when you transfer a spherical shape to a flat surface, you approximate the true shape of the Earth. Depending on the map projection you choose, some projections may cause distance between features on a map to be preserved while distortion is introduced to shape. In some cases, the area may be preserved while the direction is distorted.<\/p>\n\n\n\n<p>Cartographers choose map projections that best represent the purpose, size, and shape of the area of interest on the map.<\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The best way to represent the Earth is with a globe.  But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.<\/p>\n","protected":false},"author":2,"featured_media":18552,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kad_post_transparent":"default","_kad_post_title":"default","_kad_post_layout":"default","_kad_post_sidebar_id":"","_kad_post_content_style":"default","_kad_post_vertical_padding":"default","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[108],"tags":[291],"class_list":["post-5133","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-maps-cartography","tag-map-projections"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.6 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How Map Projections Work - GIS Geography<\/title>\n<meta name=\"description\" content=\"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/gisgeography.com\/map-projections\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How Map Projections Work - GIS Geography\" \/>\n<meta property=\"og:description\" content=\"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/gisgeography.com\/map-projections\/\" \/>\n<meta property=\"og:site_name\" content=\"GIS Geography\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/gisgeography\" \/>\n<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/gisgeography\" \/>\n<meta property=\"article:published_time\" content=\"2015-10-24T02:21:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-04-11T09:43:52+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1100\" \/>\n\t<meta property=\"og:image:height\" content=\"650\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"GISGeography\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@https:\/\/twitter.com\/GisGeography\" \/>\n<meta name=\"twitter:site\" content=\"@GisGeography\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"GISGeography\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"8 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/\"},\"author\":{\"name\":\"GISGeography\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#\\\/schema\\\/person\\\/9e7385da3acea92bc45d45be5dfe191e\"},\"headline\":\"How Map Projections Work\",\"datePublished\":\"2015-10-24T02:21:00+00:00\",\"dateModified\":\"2025-04-11T09:43:52+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/\"},\"wordCount\":1208,\"commentCount\":12,\"publisher\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2018\\\/07\\\/goode-homolosine-land.png\",\"keywords\":[\"Map Projections\"],\"articleSection\":[\"Maps &amp; Cartography\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/\",\"url\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/\",\"name\":\"How Map Projections Work - GIS Geography\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2018\\\/07\\\/goode-homolosine-land.png\",\"datePublished\":\"2015-10-24T02:21:00+00:00\",\"dateModified\":\"2025-04-11T09:43:52+00:00\",\"description\":\"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#primaryimage\",\"url\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2018\\\/07\\\/goode-homolosine-land.png\",\"contentUrl\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2018\\\/07\\\/goode-homolosine-land.png\",\"width\":1100,\"height\":650,\"caption\":\"goode map projection\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/map-projections\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/gisgeography.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Maps &amp; Cartography\",\"item\":\"https:\\\/\\\/gisgeography.com\\\/category\\\/maps-cartography\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"How Map Projections Work\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#website\",\"url\":\"https:\\\/\\\/gisgeography.com\\\/\",\"name\":\"GIS Geography\",\"description\":\"Geographic Information Systems\",\"publisher\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/gisgeography.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#organization\",\"name\":\"GIS Geography\",\"url\":\"https:\\\/\\\/gisgeography.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2015\\\/11\\\/cropped-GIS-Geography-Logo0.png\",\"contentUrl\":\"https:\\\/\\\/gisgeography.com\\\/wp-content\\\/uploads\\\/2015\\\/11\\\/cropped-GIS-Geography-Logo0.png\",\"width\":500,\"height\":100,\"caption\":\"GIS Geography\"},\"image\":{\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/gisgeography\",\"https:\\\/\\\/x.com\\\/GisGeography\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/gisgeography.com\\\/#\\\/schema\\\/person\\\/9e7385da3acea92bc45d45be5dfe191e\",\"name\":\"GISGeography\",\"description\":\"We help you learn Geographic Information Systems and remote sensing\",\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/gisgeography\",\"https:\\\/\\\/x.com\\\/https:\\\/\\\/twitter.com\\\/GisGeography\"],\"url\":\"https:\\\/\\\/gisgeography.com\\\/author\\\/gisgeo\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"How Map Projections Work - GIS Geography","description":"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/gisgeography.com\/map-projections\/","og_locale":"en_US","og_type":"article","og_title":"How Map Projections Work - GIS Geography","og_description":"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.","og_url":"https:\/\/gisgeography.com\/map-projections\/","og_site_name":"GIS Geography","article_publisher":"https:\/\/www.facebook.com\/gisgeography","article_author":"https:\/\/www.facebook.com\/gisgeography","article_published_time":"2015-10-24T02:21:00+00:00","article_modified_time":"2025-04-11T09:43:52+00:00","og_image":[{"width":1100,"height":650,"url":"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png","type":"image\/png"}],"author":"GISGeography","twitter_card":"summary_large_image","twitter_creator":"@https:\/\/twitter.com\/GisGeography","twitter_site":"@GisGeography","twitter_misc":{"Written by":"GISGeography","Est. reading time":"8 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/gisgeography.com\/map-projections\/#article","isPartOf":{"@id":"https:\/\/gisgeography.com\/map-projections\/"},"author":{"name":"GISGeography","@id":"https:\/\/gisgeography.com\/#\/schema\/person\/9e7385da3acea92bc45d45be5dfe191e"},"headline":"How Map Projections Work","datePublished":"2015-10-24T02:21:00+00:00","dateModified":"2025-04-11T09:43:52+00:00","mainEntityOfPage":{"@id":"https:\/\/gisgeography.com\/map-projections\/"},"wordCount":1208,"commentCount":12,"publisher":{"@id":"https:\/\/gisgeography.com\/#organization"},"image":{"@id":"https:\/\/gisgeography.com\/map-projections\/#primaryimage"},"thumbnailUrl":"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png","keywords":["Map Projections"],"articleSection":["Maps &amp; Cartography"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/gisgeography.com\/map-projections\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/gisgeography.com\/map-projections\/","url":"https:\/\/gisgeography.com\/map-projections\/","name":"How Map Projections Work - GIS Geography","isPartOf":{"@id":"https:\/\/gisgeography.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/gisgeography.com\/map-projections\/#primaryimage"},"image":{"@id":"https:\/\/gisgeography.com\/map-projections\/#primaryimage"},"thumbnailUrl":"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png","datePublished":"2015-10-24T02:21:00+00:00","dateModified":"2025-04-11T09:43:52+00:00","description":"The best way to represent the Earth is with a globe. But map projections can be awfully useful too. Find out why cartographers use map projections in GIS.","breadcrumb":{"@id":"https:\/\/gisgeography.com\/map-projections\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/gisgeography.com\/map-projections\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/gisgeography.com\/map-projections\/#primaryimage","url":"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png","contentUrl":"https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land.png","width":1100,"height":650,"caption":"goode map projection"},{"@type":"BreadcrumbList","@id":"https:\/\/gisgeography.com\/map-projections\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/gisgeography.com\/"},{"@type":"ListItem","position":2,"name":"Maps &amp; Cartography","item":"https:\/\/gisgeography.com\/category\/maps-cartography\/"},{"@type":"ListItem","position":3,"name":"How Map Projections Work"}]},{"@type":"WebSite","@id":"https:\/\/gisgeography.com\/#website","url":"https:\/\/gisgeography.com\/","name":"GIS Geography","description":"Geographic Information Systems","publisher":{"@id":"https:\/\/gisgeography.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/gisgeography.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/gisgeography.com\/#organization","name":"GIS Geography","url":"https:\/\/gisgeography.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/gisgeography.com\/#\/schema\/logo\/image\/","url":"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/11\/cropped-GIS-Geography-Logo0.png","contentUrl":"https:\/\/gisgeography.com\/wp-content\/uploads\/2015\/11\/cropped-GIS-Geography-Logo0.png","width":500,"height":100,"caption":"GIS Geography"},"image":{"@id":"https:\/\/gisgeography.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/gisgeography","https:\/\/x.com\/GisGeography"]},{"@type":"Person","@id":"https:\/\/gisgeography.com\/#\/schema\/person\/9e7385da3acea92bc45d45be5dfe191e","name":"GISGeography","description":"We help you learn Geographic Information Systems and remote sensing","sameAs":["https:\/\/www.facebook.com\/gisgeography","https:\/\/x.com\/https:\/\/twitter.com\/GisGeography"],"url":"https:\/\/gisgeography.com\/author\/gisgeo\/"}]}},"taxonomy_info":{"category":[{"value":108,"label":"Maps &amp; Cartography"}],"post_tag":[{"value":291,"label":"Map Projections"}]},"featured_image_src_large":["https:\/\/gisgeography.com\/wp-content\/uploads\/2018\/07\/goode-homolosine-land-678x401.png",678,401,true],"author_info":{"display_name":"GISGeography","author_link":"https:\/\/gisgeography.com\/author\/gisgeo\/"},"comment_info":112,"category_info":[{"term_id":108,"name":"Maps &amp; Cartography","slug":"maps-cartography","term_group":0,"term_taxonomy_id":109,"taxonomy":"category","description":"","parent":0,"count":77,"filter":"raw","cat_ID":108,"category_count":77,"category_description":"","cat_name":"Maps &amp; Cartography","category_nicename":"maps-cartography","category_parent":0}],"tag_info":[{"term_id":291,"name":"Map Projections","slug":"map-projections","term_group":0,"term_taxonomy_id":293,"taxonomy":"post_tag","description":"","parent":0,"count":10,"filter":"raw"}],"_links":{"self":[{"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/posts\/5133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/comments?post=5133"}],"version-history":[{"count":17,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/posts\/5133\/revisions"}],"predecessor-version":[{"id":97823,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/posts\/5133\/revisions\/97823"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/media\/18552"}],"wp:attachment":[{"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/media?parent=5133"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/categories?post=5133"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gisgeography.com\/wp-json\/wp\/v2\/tags?post=5133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}