DOWNLOAD PDF MERCATOR WORLD MAP WITH COORDINATE LINES

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1 Chapter 1 : Detailed World Map Mercator Europe-Africa One Stop Map World Coordinate Map Mercator Projection =This Mercator projection map can be configured to display just the navigational coordinate attributes of the Earth such as lines of latitude and longitude, polar and tropic circles, equator and prime meridian. Latitude and longitude values, which reference a point on the world uniquely. World coordinates, which reference a point on the map uniquely. Pixel coordinates, which reference a specific pixel on the map at a specific zoom level. Tile coordinates, which reference a specific tile on the map at a specific zoom level. World coordinates Whenever the API needs to translate a location in the world to a location on a map, it first translates latitude and longitude values into a world coordinate. The API uses the Mercator projection to perform this tranlsation. For convenience in the calculation of pixel coordinates see below we assume a map at zoom level 0 is a single tile of the base tile size. We then define world coordinates relative to pixel coordinates at zoom level 0, using the projection to convert latitudes and longitudes to pixel positions on this base tile. This world coordinate is a floating point value measured from the origin of the map projection to the specific location. Note that since this value is a floating point value, it may be much more precise than the current resolution of the map image being shown. A world coordinate is independent of the current zoom level, in other words. Note that a Mercator projection has a finite width longitudinally but an infinite height latitudinally. You can define your own projection implementing the google. Note that interfaces in the Maps JavaScript API are not classes you subclass but instead are specifications for classes you define yourself. Pixel coordinates Pixel coordinates reference a specific pixel on the map at a specific zoom level, whereas world coordinates reflect absolute locations on a given projection. Pixel coordinates are calculated using the following formula: Therefore, each higher zoom level results in a resolution four times higher than the preceding level. For example, at zoom level 1, the map consists of 4 x pixels tiles, resulting in a pixel space from x Note that for zoom level 0, the pixel coordinates are equal to the world coordinates. We now have a way to accurately denote each location on the map, at each zoom level. The API then determines logically all map tiles which lie within the given pixel bounds. Each of these map tiles are referenced using tile coordinates which greatly simplify the displaying of map imagery. Tile coordinates The API cannot load all the map imagery at once for the higher zoom levels. Instead, the API breaks up the imagery at each zoom level into a set of map tiles, which are logically arranged in an order which the application understands. When a map scrolls to a new location, or to a new zoom level, the API determines which tiles are needed using pixel coordinates, and translates those values into a set of tiles to retrieve. These tile coordinates are assigned using a scheme which makes it logically easy to determine which tile contains the imagery for any given point. Tiles in Google Maps are numbered from the same origin as that for pixels. Tiles are indexed using x,y coordinates from that origin. For example, at zoom level 2, when the earth is divided up into 16 tiles, each tile can be referenced by a unique x,y pair: Note that by dividing the pixel coordinates by the tile size and taking the integer parts of the result, you produce as a by-product the tile coordinate at the current zoom level. Example The following example displays coordinates for Chicago, IL: Use the zoom control to see the coordinate values at various zoom levels. View example and code. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3. For details, see our Site Policies. Last updated September 25, Page 1

2 Chapter 2 : Mercatorâ Help ArcGIS for Desktop The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in It became the standard map projection for nautical navigation because of its ability to represent lines of constant course, known as rhumb lines or loxodromes, as straight segments that conserve the angles with the meridians. The NOAA website states the system to have been developed by the United States Army Corps of Engineers, starting in the early s, [1] and published material[ specify ] that does state an origin apparently based on that account. From onward the US Army employed a very similar system, but with the now-standard 0. For the remaining areas of Earth, including Hawaii, the International Ellipsoid [4] was used. For different geographic regions, other datum systems e. ED50, NAD83 can be used. Prior to the development of the Universal Transverse Mercator coordinate system, several European nations demonstrated the utility of grid-based conformal maps by mapping their territory during the interwar period. Calculating the distance between two points on these maps could be performed more easily in the field using the Pythagorean theorem than was possible using the trigonometric formulas required under the graticule-based system of latitude and longitude. The transverse Mercator projection is a variant of the Mercator projection, which was originally developed by the Flemish geographer and cartographer Gerardus Mercator, in This projection is conformal, which means it preserves angles and therefore shapes across small regions. However, it distorts distance and area. Each of the 60 zones uses a transverse Mercator projection that can map a region of large north-south extent with low distortion. Distortion of scale increases to 1. The scale is less than 1 inside the standard lines and greater than 1 outside them, but the overall distortion is minimized. For more on its history, see Clifford J. However, it is often convenient or necessary to measure a series of locations on a single grid when some are located in two adjacent zones. Around the boundaries of large scale maps 1: Ideally, the coordinates of each position should be measured on the grid for the zone in which they are located, but because the scale factor is still relatively small near zone boundaries, it is possible to overlap measurements into an adjoining zone for some distance when necessary. Latitude bands[ edit ] Each zone is segmented into 20 latitude bands. Latitude bands "A" and "B" do exist, as do bands "Y" and "Z". They cover the western and eastern sides of the Antarctic and Arctic regions respectively. A convenient mnemonic to remember is that the letter "N" is the first letter in "northern hemisphere", so any letter coming before "N" in the alphabet is in the southern hemisphere, and any letter "N" or after is in the northern hemisphere. Notation[ edit ] The combination of a zone and a latitude band defines a grid zone. The zone is always written first, followed by the latitude band. For example, see image, top right, a position in Toronto, Ontario, Canada, would find itself in zone 17 and latitude band "T", thus the full grid zone reference is "17T". The grid zones serve to delineate irregular UTM zone boundaries. They also are an integral part of the military grid reference system. A note of caution: A method also is used that simply adds N or S following the zone number to indicate North or South hemisphere the easting and northing coordinates along with the zone number supplying everything necessary to geolocate a position except which hemisphere. However, this method has caused some confusion since, for instance, "50S" can mean southern hemisphere but also grid zone "50S" in the northern hemisphere. Exceptions[ edit ] These grid zones are uniform over the globe, except in two areas. The three grid zones 32X, 34X and 36X are not used. Page 2

3 Chapter 3 : Universal Transverse Mercator (UTM) Projection â GeoHub Due to this, the Mercator projection made world exploration much easier and became a essential map projection for navigation. Using a cylinder and a globe with light is a simplified explanation as to how the Mercator projection works. Mercator Without a doubt, the most famous map projection is the Mercator projection. In fact, the Mercator projection was the first projection regularly identified in atlases. It is a cylindrical map projection that is a product of its time. During the sixteenth century, new geographic information was pouring in from around the world, trade routes were being established, and sailors, explorers, and merchants needed accurate maps. Knowing this, Gerardus Mercator invented a new projection based on the cylinder. Mercator invented his map projection primarily for navigation. If you draw a straight line between two points on a map created using the Mercator projection, that line represents the direction you need to sail to travel between the two points. This type of route is called a rhumb line or loxodrome. It is not the shortest route, but if you keep the direction of your ship constant with respect to north then you will stay on course and arrive at your destination. Because the Mercator map projection is cylindrical, and a cylinder is open-ended, the projection in theory goes on forever. This example has been "trimmed" before it reached 90 degrees north and south. Because the Mercator map projection was the most commonly misused map projection during the nineteenth and twentieth centuries, many misconceptions have been propagated about the basic geography of the world. For example, Africa, the second largest continent, appears smaller than North America and Greenland. Also notice the extreme distortion at the polar regions. Some schools may still display wall maps based on the Mercator projection. You will learn more about the Mercator projection later in this session. More about Gerardus Mercator There are actually two cartographers named Mercator. The most prominent is Gerardus Mercator and the other is his son, Rumold, a prominent mapmaker in his own right. Among cartographers and geographers, the name Gerardus Mercator is not simply well-known, but is uttered with reverence. As far as we know, he was the first person to apply the term atlas to a collection of maps in book form. It has also been said that Mercator saw a new form of lettering in Italy and introduced it to Northern Europe, naming it italics in honor of its place of origin. Although neither story can be substantiated absolutely, they help form the basis of a cartographic legend. By applying a grid of intersecting lines invented centuries earlier by the Greeks to navigational maps, he paved the way for modern nautical charts. His second contribution was a map that still bears his nameâ the Mercator projection, published in No wonder future cartographers and laymen simply called it the Mercator projection. Drawing a line between two points on the map or chart shows a sailor the direction he needs to sail. Page 3

4 Chapter 4 : Mercatorâ Help ArcGIS Desktop All meridians can be projected, but the upper and lower limits of latitude are approximately 80Â N and S. Large area distortion makes the Mercator projection unsuitable for general geographic world maps. They share the same underlying mathematical construction and consequently the transverse Mercator inherits many traits from the normal Mercator: Both projections are cylindrical: For the transverse Mercator, the axis of the cylinder lies in the equatorial plane, and the line of tangency is any chosen meridian, thereby designated the central meridian. Both projections may be modified to secant forms, which means the scale has been reduced so that the cylinder slices through the model globe. Both exist in spherical and ellipsoidal versions. Both projections are conformal, so that the point scale is independent of direction and local shapes are well preserved; Both projections have constant scale on the line of tangency the equator for the normal Mercator and the central meridian for the transverse. Since the central meridian of the transverse Mercator can be chosen at will, it may be used to construct highly accurate maps of narrow width anywhere on the globe. The secant, ellipsoidal form of the transverse Mercator is the most widely applied of all projections for accurate large-scale maps. Spherical transverse Mercator[ edit ] In constructing a map on any projection, a sphere is normally chosen to model the Earth when the extent of the mapped region exceeds a few hundred kilometers in length in both dimensions. For maps of smaller regions, an ellipsoidal model must be chosen if greater accuracy is required; see next section. The spherical form of the transverse Mercator projection was one of the seven new projections presented, in, by Johann Heinrich Lambert. All other meridians project to complicated curves. The poles lie at infinity. The points on the equator at ninety degrees from the central meridian are projected to infinity. The shapes of small elements are well preserved. The projection is not suited for world maps. Distortion is small near the equator and the projection particularly in its ellipsoidal form is suitable for accurate mapping of equatorial regions. Distortion is small near the central meridian and the projection particularly in its ellipsoidal form is suitable for accurate mapping of narrow regions. On the sphere it depends on latitude only. The scale is true on the equator. It is a function of x on the projection. On the sphere it depends on both latitude and longitude. The scale is true on the central meridian. The two lines are not meridians. Grid north and true north coincide. It increases as the poles are approached. Grid north and true north do not coincide. The projection is conformal with a constant scale on the central meridian. This was proved to be untrue by British cartographer E. Thompson, whose unpublished exact closed form version of the projection, reported by L. Lee in, [8] showed that the ellipsoidal projection is finite below. This is the most striking difference between the spherical and ellipsoidal versions of the transverse Mercator projection: Features[ edit ] Near the central meridian Greenwich in the above example the projection has low distortion and the shapes of Africa, western Europe, the British Isles, Greenland, and Antarctica compare favourably with a globe. The central regions of the transverse projections on sphere and ellipsoid are indistinguishable on the small-scale projections shown here. The more distant hemisphere is projected above the north pole and below the south pole. The equator bisects Africa, crosses South America and then continues onto the complete outer boundary of the projection; the top and bottom edges and the right and left edges must be identified i. Distortion increases towards the right and left boundaries of the projection but it does not increase to infinity. The map is conformal. Lines intersecting at any specified angle on the ellipsoid project into lines intersecting at the same angle on the projection. The point scale factor is independent of direction at any point so that the shape of a small region is reasonably well preserved. The necessary condition is that the magnitude of scale factor must not vary too much over the region concerned. Note that while South America is distorted greatly the island of Ceylon is small enough to be reasonably shaped although it is far from the central meridian. The choice of central meridian greatly affects the appearance of the projection. Direct series for scale, convergence and distortion are functions of eccentricity and both latitude and longitude on the ellipsoid: In the secant version the lines of true scale on the projection are no longer parallel to central meridian; they curve slightly. The convergence angle between projected meridians and the x constant grid lines is no longer zero except on the equator so that a grid bearing must be corrected to obtain an azimuth from true north. The difference is Page 4

5 small, but not negligible, particularly at high latitudes. Formulae for the direct projection, giving the coordinates x and y, are fourth order expansions in terms of the third flattening, n the ratio of the difference and sum of the major and minor axes of the ellipsoid. Redfearn extended the series to eighth order and examined which terms were necessary to attain an accuracy of 1 mm ground measurement. The Redfearn series are the basis for geodetic mapping in many countries: Australia, Germany, Canada, South Africa to name but a few. A list is given in Appendix A. For an example of modifications which do not have this status see Transverse Mercator: All such modifications have been eclipsed by the power of modern computers and the development of high order n-series outlined below. The precise Redfearn series, although of low order, cannot be disregarded as they are still enshrined in the quasi-legal definitions of OSGB and UTM etc. Page 5

6 Chapter 5 : Coordinates on a map - pick GPS lat & long or coordinates in a projection system The Peters projection map used a rectangular coordinate system that showed parallel lines of latitude and longitude. Skilled at marketing, Arno claimed that his map more fairly displayed third world countries than the "popular" Mercator projection map, which distorts and dramatically enlarges the size of Eurasian and North American countries. Additional information Highly detailed world map Europe-Africa centered Mercator projection. This map shows countries, capitals, cities, rivers, geographic lines, grid lines, lakes and state-provinces for Australia, Canada, and the US. Each layer is divided into several sublayers for easy management. Cities are divided into capitals, admin-1 capitals for Australia, Canada, and the US and six scale ranks. The scale ranks are not based on the actual population size of a city. There is no up-to-date data available for this. Instead, we chose to divide the cities into scale ranks based on their importance in their local neighborhood. This is a much more relevant approach for a quality world map. Rivers and lakes are each divided into six scale ranks. The map has been drawn in our map style Lucid and Adobe Illustrator graphic styles are provided for every element. Via the Illustrator character styles palette you can easily change the size of the text without breaking the Lucid map style. This map comes in a printable version and an editable vector version. The printable option includes two file formats: The JPEG is extremely large: The PDF is non-layered, has no editable text, but is scalable to any size without loss of quality. A vector map can easily be scaled up or down to any size you want without loss of quality. The text is real text. As part of our support when you buy this map, you can always contact us to retrieve yet another file format. Be sure to create an account upon purchase of this map. You will be entitled to free lifetime map updates, so your world map stays up-to-date no matter what. This vector world map comes with a royalty-free license. It means you can use it for personal and commercial use. Page 6

7 Chapter 6 : Map and Tile Coordinates Maps JavaScript API Google Developers Because the Mercator map projection was the most commonly misused map projection during the nineteenth and twentieth centuries, many misconceptions have been propagated about the basic geography of the world. As in all cylindrical projections, parallels and meridians are straight and perpendicular to each other. In accomplishing this, the unavoidable east-west stretching of the map, which increases as distance away from the equator increases, is accompanied in the Mercator projection by a corresponding north-south stretching, so that at every point location the east-west scale is the same as the north-south scale, making it a conformal map projection. Conformal projections preserve angles around all locations. Because the linear scale of a Mercator map increases with latitude, it distorts the size of geographical objects far from the equator and conveys a distorted perception of the overall geometry of the planet. All lines of constant bearing rhumbs or loxodromesâ those making constant angles with the meridians are represented by straight segments on a Mercator map. The two properties, conformality and straight rhumb lines, make this projection uniquely suited to marine navigation: Although the method of construction is not explained by the author, Mercator probably used a graphical method, transferring some rhumb lines previously plotted on a globe to a square graticule grid formed by lines of latitude and longitude, and then adjusting the spacing between parallels so that those lines became straight, making the same angle with the meridians as in the globe. The development of the Mercator projection represented a major breakthrough in the nautical cartography of the 16th century. However, it was much ahead of its time, since the old navigational and surveying techniques were not compatible with its use in navigation. Two main problems prevented its immediate application: Only in the middle of the 18th century, after the marine chronometer was invented and the spatial distribution of magnetic declination was known, could the Mercator projection be fully adopted by navigators. Several authors are associated with the development of Mercator projection: German Erhard Etzlaub c. Portuguese mathematician and cosmographer Pedro Nunes â, who first described the loxodrome and its use in marine navigation, and suggested the construction of a nautical atlas composed of several large-scale sheets in the cylindrical equidistant projection as a way to minimize distortion of directions. If these sheets were brought to the same scale and assembled an approximation of the Mercator projection would be obtained English mathematician Edward Wright c. English mathematicians Thomas Harriot â and Henry Bond c. Uses[ edit ] The Mercator projection portrays Greenland as larger than Australia; in actuality, Australia is more than three and a half times as large as Greenland. The Mercator projection exaggerates areas far from the equator. Africa also appears to be roughly the same size as Europe, when in reality Africa is nearly 3 times larger. Antarctica appears as the biggest continent and would be infinitely large on a complete map, although it is actually the fifth in area. A relation between the Mercator projection and the true size of each country. The Mercator projection is still used commonly for navigation. On the other hand, because of great land area distortions, it is not well suited for general world maps. Therefore, Mercator himself used the equal-area sinusoidal projection to show relative areas. However, despite such distortions, Mercator projection was, especially in the late 19th and early 20th centuries, perhaps the most common projection used in world maps, despite being much criticized for this use. The Mercator projection is still commonly used for areas near the equator, however, where distortion is minimal. Arno Peters stirred controversy when he proposed what is now usually called the Gallâ Peters projection as the alternative to the Mercator. The projection he promoted is a specific parameterization of the cylindrical equal-area projection. In response, a resolution by seven North American geographical groups deprecated the use of cylindrical projections for general purpose world maps, which would include both the Mercator and the Gallâ Peters. Maps, and others use a variant of the Mercator projection for their map images [8] called Web Mercator or Google Web Mercator. Many different methods exist for calculating a. The simplest include a the equatorial radius of the ellipsoid, b the arithmetic or geometric mean of the semi-axes of the ellipsoid, c the radius of the sphere having the same volume as the ellipsoid. These are the values used for numerical examples in later sections. Only high-accuracy cartography on large scale maps requires an ellipsoidal model. Cylindrical projections[ edit ] The spherical approximation of Earth with radius a can be Page 7

8 modelled by a smaller sphere of radius R, called the globe in this section. The globe determines the scale of the map. The various cylindrical projections specify how the geographic detail is transferred from the globe to a cylinder tangential to it at the equator. The cylinder is then unrolled to give the planar map. For example, a Mercator map printed in a book might have an equatorial width of In general this function does not describe the geometrical projection as of light rays onto a screen from the centre of the globe to the cylinder, which is only one of an unlimited number of ways to conceptually project a cylindrical map. Since the cylinder is tangential to the globe at the equator, the scale factor between globe and cylinder is unity on the equator but nowhere else. For small elements, the angle PKQ is approximately a right angle and therefore tan. Page 8

9 Chapter 7 : Transverse Mercator projection - Wikipedia I have a line (Ax,Ay - Bx,By) over a mercator projection (google maps) and a random point (Cx,Cy) nearest to that line, i would to know the closest point (transparent blue on the image) over that line to point (blue in the image). In most projections, it runs down the middle of the map and the map is symmetrical on either side of it. It may or may not be a line of true scale. True scale means no distance distortion. In ArcGIS, you can change the central meridian of any projection. The central meridian is also called the longitude of origin or the longitude of center. Its intersection with the latitude of origin see below defines the starting point of the projected x,y map coordinates. Every projection also has a latitude of origin. The intersection of this line with the central meridian is the starting point of the projected coordinates. In ArcGIS, you can put the latitude of origin wherever you want for most conic and transverse cylindrical projections. The latitude of origin may or may not be the middle latitude of the projection and may or may not be a line of true scale. Locations are measured in latitude and longitude, as you know from the previous module. But when you set a projection and flatten everything out, you also start using a new way to measure location. This new way is in terms of constant distance units like meters or feet measured along a horizontal x-axis and a vertical y-axis. The place where the axes cross is the coordinate origin, or 0,0 point. In the top graphic below, the intersection of the central meridian longitude of origin and the latitude of origin is marked with a cross. This point becomes the origin of the x,y coordinates. The point of intersection of the central meridian and latitude of origin becomes the origin of the x,y coordinates. Red lines represent the x and y axes. The bottom graphic shows the grid normally invisible on which the x,y coordinates are located. The heavy lines are the x- and y-axes, which divide the grid into four quadrants. Coordinates are positive in one direction and negative in the other for each axis. In essence, a map projection is a method for taking locations on a sphere, as defined by the intersection of a meridian and a parallel, and assigning them to locations on a grid, as defined by the intersection of an x-axis and a y-axis. You can help make this happen by setting the latitude of origin below the area of interest, ensuring that all y-coordinates on the map are positive. The same result can be achieved with false northing, discussed in the next concept. A standard parallel is a line of latitude that has true scale. Not all projections have standard parallels, but many common ones do. Conic projections often have two. In a few projections, like the Sinusoidal and the Polyconic, every line of latitude has true scale and is therefore a standard parallel. In ArcGIS, you can change the standard parallel for some projections and not for others. Many world projections, for instance, have fixed standard parallels. These do not show up as parameters when you set the projection, but you can find out what they are in the online help. A standard parallel may or may not coincide with the latitude of origin. The Cylindrical Equal Area projection has a single standard parallel. By default, it is the equator, but you can change it. These standard parallels define the projection and cannot be changed. In some projections, you will also see parameters called the latitude of center and the central parallel. These two terms seem to have the same meaning. Like the latitude of origin, they define the starting point of the y-coordinates; unlike it, they are nearly always the middle parallel of the projection. These parameters are used mainly with projections that have single points rather than lines of zero distortion, such as the Gnomonic and Orthographic. The intersection of the latitude of center or central parallel with the central meridian defines both the origin of the x,y coordinates and the point of zero distortion for the projection. A summary of angular parameters. Other angular parameters are used only with a few specific projections, like the Two Point Equidistant and the Hotine Oblique Mercator. For example, the Hotine Oblique Mercator has special parameters for defining an oblique line of true scale. You used these parameters in a previous exercise. Page 9

10 Chapter 8 : Mercator projection - Wikipedia As a quick rundown, it was invented by Gerardus Mercator in the mid-late 's and was designed to represent the world by solely using straight-line coordinates. While this does not make it the most accurate projection in the world, it still serves as a good map for navigation as it preserves direction. Therefore, UTM is a conformal transverse projection. UTM is the most widely used projection in Kenya. Concept UTM projection divides the earth into 60 zones each 6 degrees of longitude wide. There is a reference for UTM grid coordinates within each zone. UTM zones extend from 80 degrees south to 84 degrees north. Polar Regions use the Universal Polar grid system to be discussed in a different post. The zones are numbered, starting at the International Date Line, at longitude degrees, and proceeding east. Each zone is further divided horizontally into bands spanning 8 degrees of latitude. These bands are lettered south to north, from 80 degrees south with letter C to 84 degrees north with letter X. Letters I and O are skipped to avoid confusion with numbers 1 and 0. Band X spans 12 degrees of latitude. If you are in the western hemisphere, the value you get is your zone. If you are in the eastern hemisphere, your zone is the value you obtain plus I am in Nairobi Kenya. The center is clearly 39 which in this case is the central meridian. Coordinates UTM coordinates are expressed in meters to the east, referred to as the Easting X, and a distance to the north referred to as the Northing Y. UTM easting coordinates are referenced to the center line of the zone known as the central meridian. The central meridian is assigned an easting value of, meters East. Minimum and maximum easting values are: For locations north of the equator the equator is assigned the northing value of 0 meters North. To avoid negative numbers, locations south of the equator are made with the equator assigned a value of 10,, meters North. Some UTM northing values are valid both north and south of the equator. In order to avoid confusion the full coordinate needs to specify if the location is north or south of the equator. Usually this is done by including the letter for the latitude band. The scale then increases on either on either side until it becomes 1 on the slightly curved lines approximately kilometers on either side. The scale keeps increasing after this to the end of the zone. See diagram above for illustration. Page 10

11 Chapter 9 : The UTM Grid and Transverse Mercator Projection The Nature of Geographic Information Figure A Mercator projection of the world, showing the 60 UTM coordinate system zones, each divided into north and south halves at the equator. Parameters Description Originally created to display accurate compass bearings for sea travel, an additional feature of this projection is that all local shapes are accurate and clearly defined. A sphere-based version of Mercator is used by several web mapping sites. Two methods exist for emulating the Mercator projection used by the web services. If the Mercator implementation supports spheroids ellipsoids, the projected coordinate system must be based on a sphere-based geographic coordinate system. This will force the use of sphere equations. The implementation of Mercator auxiliary sphere has sphere equations only. In addition, it has a projection parameter that identifies what to use for the sphere radius if the geographic coordinate system is ellipsoidal based. The default value of zero 0 uses the semimajor axis. Projection method This is a cylindrical projection. Meridians are parallel to each other and equally spaced. The lines of latitude are also parallel but become farther apart toward the poles. The poles cannot be shown. Small shapes are well represented because this projection maintains the local angular relationships. Area Area is increasingly distorted toward the polar regions. For example, although Greenland is only one-eighth the size of South America, Greenland appears to be larger in the Mercator projection. Direction Any straight line drawn on this projection represents an actual compass bearing. These true direction lines are rhumb lines and generally do not describe the shortest distance between points. Distance Scale is true along the equator or along the secant latitudes. Limitations The poles cannot be represented on the Mercator projection. Large area distortion makes the Mercator projection unsuitable for general geographic world maps. Uses and applications Standard sea navigation charts direction Other directional uses: Page 11