The military grid reference system mgrs is the pair, utm and ups, after some reformat. Various countries use this projection for their topographic maps. Universal transverse mercator utm and universal polar stereographic ups. A projected coordinate system based on a map projection such as transverse mercator, albers equal area, or robinson, all of which along with numerous other map projection models provide various mechanisms to project maps of the earths spherical surface onto a two. Working with map projections and coordinate systems in. Each of these zones is 6 degrees wide, apart from a few exceptions around norway and svalbard.
Kotsakis objectives in these noteswe develop a body of theory to understand and analyse the distortion properties of maps that underlie different map projection algorithms. Universal transverse mercator utm coordinate system is a standard set of map projections with a central meridian for each sixdegree wide utm zone. Utm zones are flattened using the transverse mercator projection, and a rectangular grid network of straight horizontal and vertical lines is superimposed on each zone. Coordinate systems, map projections, and geographic datum. A mercator projection is like when someone puts a can around the earth and then rolls the earth onto the inside of the can and lays it out flat as a map. All projections create some distortion in the map, so when we choose a projection, we should be aware of those distortions. Map projection is very important because it is the bedrock of map based construction. Project the globe onto a 2d surface there are lots of ways to do each step, resulting in lots of coordinate reference systems. The mercator projection is a cylindrical map projection presented by the flemish geographer and cartographer gerardus mercator in 1569. There is a reference for utm grid coordinates within each zone. Universal transverse mercator utm projection geohub. The universal transverse mercator utm grid map projections the most convenient way to identify points on the curved surface of the earth is with a system of reference lines called parallels of latitude and meridians of lon gitude. At the same time, utm projection and gausskruger projection are also. The cylinder in the transverse mercator projection is tangent along a meridian line of longitude or it is secant, in which case it cuts through the earth at two standard meridians.
The mercator projection was used for its portrayal of direction and. The universal transverse mercator utm is a system for assigning coordinates to locations on the surface of the earth. Dutch topographic map 1996 civil bessel ellipsoid rd map grid military. Maps using the projection can show the whole earth, but directions, distances, and areas are reasonably accurate only within 15 of the central meridian. The utm is a transverse mercator to which specific parameters, such as standard central meridians, have been applied snyder, 1987, p. Map projections explained a beginners guide youtube. The universal transverse mercator the gausskruger version of the transverse mercator projection covers latitudes from 80s to 84n. Report the positions of the following symbols in 100m abbreviated format. The transverse mercator map projection is an adaptation of the standard mercator projection which flips the cylinder 90 degrees transverse. The universal transverse mercator utm, state plane, and gausskruger coordinate systems all use this map projection. Universal transverse mercator utm developed by military grid system earth divided into 60 zones great for small areas minimal map distortion distortion greater at edge of zones most common map projection used 20. In the translation from a spherical surface to a twodimensional, flat surface, a. Under related information below, click the link titled projections table 2009 to access. Because many administrative areas cross utm zone boundaries but are stored as features in a same dataset, a decision is then made in which utm.
Wgs 84 utm zone 48n is a crs for large and medium scale topographic mapping and engineering survey. Department of defense dod and taken together cover the whole earth. The world is divided into 60 north and south zones, each six degrees wide. Web mercator is a slight variant of the mercator projection, one used primarily in webbased mapping programs. The parameters needed to convert to or from utm zone 15 are shown below. Page 4 engo 421 map projections lecture notes on map projections engo 421.
The system instead divides the earth into sixty zones, each a sixdegree band of longitude, and uses a secant transverse mercator projection in each zone. Lecture 2 map projections and gis coordinate systems. Although meridians inside the zone and on zone boundaries converge towards. The utm grid military grid reference system natural. This means, it is generally used all over the world. Each zone has its own central meridian and a scale factor of 0. Some measurement framework systems define both projections and coordinate systems. In this grid, the world is divided into 60 northsouth zones. When readogr is used to import these data this information is automatically linked to the r.
Distortion of scale, distance, direction and area increase away from the central meridian. For example, the universal transverse mercator utm system, commonly used by scientists and federal organizations, is based on a series of 60 transverse mercator projections, in which different areas of the earth fall into different 6degree zones. Learn what a map projection is, why they are used and what impact they have on maps gis systems. The central meridian, 0, for each zone is assigned a false easting, e 0,of 500,000 m. At present, utm projection is used to compile topographic map by the majority of nations in the world, such as america, japan, canada, france, brazil, switzerland, etc, but gausskruger projection is used by other nations, such as china, vietnam, d.
D h maling, coordinate systems and map projections. Map projection utm geonet, the esri community gis and. Six conformal map projections, including utm zones 38 to 41, lcc2sp and obsolete tm, are mostly used in iran. Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the. Therefore, utm is a conformal transverse projection.
Map projections massachusetts institute of technology. Army adopted the utm projection and grid for designating rectangular coordinates on largescale maps for the entire world. Transverse mercatorproperties of maps documentation. Working with map projections and coordinate systems in arcgis. Universal transverse mercator utm coordinate system. A sound knowledge of map projections and grids requires an understanding of the mathematical nature of projections and the size and shape of the earth, since in our context. Map base construction, the first stage of map making processes, involves the projection and coordinate systems on which compilation, the second stage will take place.
Utm zones extend from 80 degrees south to 84 degrees north. The utm projection flattens the sphere 60 times by shifting the cylinder central meridian 6 for each zone. Try it out using your overlay and the following map. Utm zones should not be combined novice utm users usually do not realize that each utm zone is in fact a different. Between those scales, choosing to use a sphere or spheroid will depend on the maps purpose and the accuracy of the data. The distortion in the projection increases from the center toward the eastern and western extremes of the state. Analysis of map projection distortion for utmk article pdf available in journal of the korean society of surveying geodesy photogrammetry and cartography 244 october 2006 with 55 reads. Handbook for transformation of datums, projections, grids and. The geoid is defined as the surface of the earths gravity field, which is approximately the same as mean sea level. The equal earth map projection is a new equalarea pseudocylindrical projection for world maps. Intro to coordinate systems and utm projection youtube. Apr 08, 2016 please watch before class on tuesday 44.
The projection from spheroid to a utm zone is some parameterization of the transverse mercator projection. The utm coordinate system is a universally used plane coordinate system except for polar regions. Note that the map, which uses a global mercator projection, shows the zones in lines of parallel meridians ns lines and distorts the map most nearest the poles, and least nearest the equator. These map projections are endowed with parameters for general utility, of which utm and ups are particular instances. The universal transverse mercator grid the national imagery and mapping agency nima formerly the defense mapping agency adopted a special grid for military use throughout the world called the universal transverse mercator utm grid. The 1,000meter value of the ticks is shown for every tick or grid line. Transverse mercator is based on equations published by john p. On some maps, the meridians and parallels appear as straight lines. However, the web mercator uses the spherical formulas at all scales whereas largescale mercator maps normally use the ellipsoidal form of the projection. Now the yvalues increase southwards and the xvalues increase to the west. There are 60 zones in the universal transverse mercator map projection, each nominally 6 wide.
This can become part of a file used in arcinfos project command. Sep 29, 2017 therefore, utm is a conformal transverse projection. It uses the same formulas as the standard mercator as used for smallscale maps. It is the representation of the objects and information on a curved surface in a plane using mathematical and geometric relations.
The military grid reference system is convenient, but unfortunately reference numbers repeat themselves every 100,000 metres 100 km or about 62 miles. It is perpendicular to the direction of gravity pull. Other stages are generalization, production and revision when necessary olomo and ufuah. In the translation from a spherical surface to a twodimensional, flat surface, a change in the expression of points occurs. Relationship and applications of utm projection and gauss. Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the shape of the geoid is irregular. Select a suitable map projection or coordinate system. Nov 05, 2016 nepal lies in the utm zone of 44 0 n and 45 0 n.
To select a map projection, determine which of the properties is the most important for the project, and select the coordinate system or map projection that best preserves that property. Map projections do not, in general, preserve straight lines, so this requires considerable computation. Zone centerline that is closest to it and then makes a map using that utm zone cylindrical projection. It is also a conformal projection that preserves angles and a linear point scale that is equal in all directions around any point. A map projection is the systematic transformation of locations on the earth latitudelongitude to planar coordinates the basis for this transformation is the geographic coordinate system which references a datum map projections are designed for specific purposes. Introduction to the utm coordinate system measure evaluation. Scale factor is a unitless value applied to the center point or centerline of a map projection. We will taker a closer look at the popular mercator projection and examine how the projection. The universal transverse mercator is horrible for smallscale lessdetailed maps like world atlases and perfect for mapping narrow regions. Universal transverse mercator coordinate system wikipedia. With utm coordinates always check ellipsoid and projection. Implementation practice web mercator map projection.
The universal transverse mercator utm is a system for assigning coordinates to locations on. A false easting of 500,000 meters and a false northing of 4,500,000 meters are used. The mercator projection is a cylindrical projection that was developed for navigation purposes. Most usgs digital products are projected on the universal transverse mercator utm, regardless of the projection of the corresponding topographic map. To map any spot on earth, one picks the utm zone centerline that is closest to it and then makes a map using that utm zone cylindrical projection. The scale factor is usually slightly less than one. The universal transverse mercator utm grid usgs publications. Transverse mercator projection central meridian is selected by the map maker and touches the cylinder. A sphere is based on a circle, while a spheroid or. The mercator projection is a conformal, cylindrical projection. In addition, the actual meter value is shown for ticks nearest the southeast and northwest corners of the map.
However, it differs from global latitudelongitude in that it divides earth into 60 zones and projects. But how does the universal transverse mercator work. Utm grid zones of the world compiled by alan morton. The universal transverse mercator utm coordinate system is a specialized application of the transverse mercator projection. The points symbolize residential homes the grid overlays the state of virginia which falls into two utm zones 17,18 but most of the state is in 17. Therefore a method has been devised to identify the 100,000metre squares by letters which are printed in blue on the face of all nts maps. As the name suggests, the universal transverse mercator projection is based on the cylindrical transverse mercator projection. Conformal map projections conformality was recognized as an important and desirable property for map projections used. To discuss this subject the joint research centre asked eurogeographics to organise a second workshop in december 2000 which the main objective was to analyse the european commission primary needs for map projection s and obtain expert advice to select an appropriate set of european conventional reference. There are 60 longitudinal projection zones numbered 1 to 60 starting at 180w. Since some provinces extends to more than one zone, optimum selection of a map. This system centers a utm like zone on the 90th meridian west, thereby covering the state with one zone.
Utm projection divides the earth into 60 zones each 6 degrees of longitude wide. It works best for smaller areas closer to the equator. A map projection is a rigorous mathematical means of translating a particular region of our earths curvaceous threedimensional surface into a flat twodimensional representation. Only the tm and utm projections are considered in this paper. The universal grids, universal transverse mercator utm and universal polar stereographic ups, were devised by the u. If you measure the azimuth on the map and then sail this azimuth constantly, you will reach the destination.
The zones are bounded by meridians 3 either side of a central meridian. This gives cartographers a map to work with always in meters. Map projections displaying the earth on 2 dimensional maps the world from space. More detailed examples showing complete conversions are shown in the nad83 minnesota county coordinate system section of this. It should be noted that the previous edition, 3, had these same purposes. Dec 08, 2015 these grid label points are very important for what im using the map for. The idea is th at drawing a straight line on the map between two points produces the correct sailing azimuth. Handbook for transformation of datums, projections, grids. The universal grids and the transverse mercator and polar. Pdf evaluation of utm and lcc2sp map projections, case. Wgs 84 utm zone 48n uses the wgs 84 geographic 2d crs as its base crs and the utm zone 48n transverse mercator as its projection. This map projection is practical for nautical applications due to its ability to represent lines of constant course, known as rhumb lines, as straight segments that conserve the angles with the meridians.
Snyder and the defense mapping agency technical manual. Click on the map to get a pdf file containing this exercise. It was invented to produce maps of large areas that was conformal. The universal transverse mercator coordinate system was developed by the united states army corps of engineers in the 1940s.
However, to maintain accuracy for largerscale maps scales of 1. Some spatial data files have associated projection data, such as esri shapefiles. Jun 06, 2017 map projection a map projection is a systematic transformation of the latitudes and longitudes of locations on the surface of a sphere or an ellipsoid into locations on a plane. The department of defense replaced wpg with the conformal utm system in the 1940s. The universal transverse mercator utm projection is used to define horizontal positions worldwide by dividing. The projection is good for keeping angles and shapes correct, but large shapes and size are distorted. Utm projection contd utm is suitable as a map projections for areas whose width is similar to the width of one utm zone. To go back and forth between data frames, rightclick on the data frame name and select activate. Utm zones for africa range from 28 to 39 and include both the n and s hemispheres. The transverse mercator map projection is an adaptation of the standard mercator projection. Analysis of universal transverse mercator projection and. The transverse version is widely used in national and international mapping systems around the world, including the utm. It looks similar to the widely used robinson projection, but unlike the robinson projection, retains. Although the earth is best represented by a spheroid.
How universal transverse mercator utm works gis geography. Like the traditional method of latitude and longitude, it is a horizontal position representation, which means it ignores altitude and treats the earth as a perfect ellipsoid. The utm coordinate system, which uses the transverse mercator projection, has a scale factor of 0. Australian geodetic datum agd, one conformal map projection. A map a 2d representation of the 3d earth with eastingnorthing coordinates an overview of ellipses, datums, and projections the projection. Jan 06, 2017 learn what a map projection is, why they are used and what impact they have on maps gis systems.