Selecting a map projection national geographic society. Mollweide projection babinet, homalographic, homolographic, elliptical projection is a pseudocylindrical equal area map projection generally used for global maps of the world or sky. Its other names include the homolographic, the homalographic, the babinet, and the elliptical projections. The projection trades accuracy of angle and shape for accuracy of proportions in area. Armed forces military maps show the earth drawn to scale as you would see it from above the military uses the universal transverse mercator utm and the universal polar stereographic ups grid system. For the normal aspect, the apex of the cone lies on the polar axis of the earth. Map makers attempt to transfer the eartha round, spherical globeto flat paper. Because the mollweide is sometimes called the homolographic projection, goode fused the two names homolographic and sinusoidal to create the name homolosine. Orthomorphic or trueshape projection is one in which shapes of various areas are portrayed correctly.
The north to south stretching equals east to west but grows with latitude faster than east to west stretching in the case of central cylindrical projection. It is that projection in which areas of various parts of the earth are represented correctly. As mentioned above, the correctness of area, shape, direction and distances are the four major global properties to be. Goodes procedure was to use the sinusoidal projection. A map projection is used to portray all or part of the round earth on a flat surface. Usgs topographic map based on the transverse mercator projection is nearly correct in every respect. To represent parts of the surface of the earth on a flat paper map or on. The projected graticule shown above is the result of an azimuthal equidistant projection in its normal polar aspect.
Second, that subsequent layers that have their coordinate systems defined can be transformed onthefly to overlay coherently with the other layers in the map, regardless coordinate systems inherent in the other layers. Pseudocylindrical in standard presentation, these map the central meridian and parallels as straight lines. The homolosine projection, popular in atlases, was first described by professor john paul goode in 1925. This requires a systematic transformation of the latitudes and longitudes of locations from the surface of the globe into locations on a plane.
Practical work in geography class 11 solutions chapter 4 map projections. If it is tangential to a point between the pole and the equator, it is called the oblique projection. Out of more than 200 different map projections images you can select two at a time to view their. A geographic coordinate systems pdf file which contains lists of supported gcs and vcs. A map projectionis a mathematically described technique of how to represent the earths curved surface on a flat map. This usually includes lines delineat ing meridians and parallels, as required by some definitions of a map projection, but it may not, depending on the purpose of the map. Projection is also called homolographic projection. Dec 27, 2002 a map projection is one of many methods used to represent the 3dimensional surface of the earth or other round body on a 2dimensional plane in cartography mapmaking. Planar, azimuthal or zenithal projection this type of map projection allows. Such a representation presents an obvious problem but one that did not disturb ancient or medieval cartographers. It is also known as the babinet projection, homalographic projection, homolographic projection, and elliptical projection. Angles, areas, directions, shapes, and distances can become distorted when transformed from a curved surface to a plane.
Also called babinet, elliptical, homolographic, or homalographic, carl b. This is a summary of map projections that have articles of their own on wikipedia or that are. In order to portray the surface of a round body on a twodimensional flat plane, you must first define a developable surface i. It is the only projection that can accurately represent both areas and true direction from the center of the projection. Choose the right answer from the four alternatives given below. A sphere is based on a circle, while a spheroid or. Also called babinet, elliptical, homolographic, or. Types of map projections many types of map projections are being used for. Maps and map reading are essential skills that all of.
Oct 01, 2015 types of map projections many types of map projections are being used for map making. Use equal area projections for thematic or distribution maps. A tutorial on map projections and geographic coordinate systems. All parallels are straight lines, and all meridians are equally spaced elliptical arcs. 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. The goode homolosine projection or interrupted goode homolosine projection is a pseudocylindrical, equalarea, composite map projection used for world maps.
The circle gives the impression that worcester is approximately the same distance from boston as new hampshire, and that the state is nearly five times longer, east to west, as it is northtosouth. Types of map projections many types of map projections are being used for map making. Interrupted map projection there are many different types of this projection. Homolographic projection definition is an equalarea map projection. They are basically classified into four groups in accordance with the map projection theory or the types of surfaces that are tangent with the globe. Only a globe can represent accurately the shape, orientation, and relative area of the earths surface features. A map projection is needed to show the spherical surface of the earth on a flat map see whats a map projection. The shape is generally maintained at the cost of the correctness of area. Map projections are the different techniques used by cartographers for presenting a round globe on a flat surface. Although the projection procedure inevitably introduces systematic spatial distortions, particular types of distortion can be minimized to suit the geographic scope and intended use of the map data. The map of the moon, published in the february 1969 issue of national geographic magazine, was the first map to show the entire lunar surfaceincluding the far side of the moonon a single sheet of paper. It is an equalarea projection designed for smallscale maps. Common in the 1960s, the goode homolosine projection is often called an orangepeel map because of its resemblance to the flattened rind of a handpeeled orange. A projection in which the network of latitudes and longitudes is developed in such a way that every graticule on the map is equal in area to the corresponding graticule on the globe.
A sphere, unlike a polyhedron, cone, or cylinder, cannot be reformed into a plane. Between those scales, choosing to use a sphere or spheroid will depend on the maps purpose and the accuracy of the data. This publication is a major revision of usgs bulletin 1532, which is titled map. The field of map projections concerns itself with the ways of translating the curved surface of the earth into a flat map. This site ist about map projections, specifically about world map projections. Map projection definition of map projection by the free. Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the. Map projection article about map projection by the free. Planar, azimuthal or zenithal projection conic projection cylindrical projection mathematical or conventional projection. This booklet provides a conceptual introduction to map projections and geographic reference systems. The map of massachusetts in unprojected decimal degrees of longitude and latitude note the proportion of the lines and the circle. Ncert solutions class 11 geography chapter 4 map projections. Sep 04, 2015 email tweet share share on facebook pin pocket whatsapp telegram map projections are a key component to every map. In cartography, a map projection is a way to flatten a globes surface into a plane in order to make a map.
A map projection is a systematic representation of all or part of the surface of a round body, especially the earth, on a plane. This booklet provides a conceptual introduction to. Email tweet share share on facebook pin pocket whatsapp telegram map projections are a key component to every map. 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. The geoid is defined as the surface of the earths gravity field, which is approximately the same as mean sea level. The maps purpose narrows your choices, but doesnt determine a projection. In effect, a projection is a systematic method of drawing the earths meridians and parallels on a flat surface. A map projection is a systematic transformation of the latitudes and longitudes of positions on the surface of the earth to a. It is carried out by an orderly and systematic representation of the parallels of latitude and the meridians of longitude of the spherical earth or part of it on a plane surface on a conveniently chosen scale. A great variety of map projections has been devised to provide for the various properties that may be desired in maps. Interrupted goode homolographic continental unities.
The problem of map projection is stated, and the basic terminology is introduced. Practical work in geography class 11 solutions chapter 4 map. Presentation maps are usually conformal projections, although compromise and equal area projections can also be used. Understanding map projections landing page for kartoweb. Do the test and share with us your score of facebook or twitter. Jul 30, 2019 practical work in geography class 11 solutions chapter 4 map projections class 11 practical work in geography chapter 4 ncert textbook questions solved 1. Download ncert solutions class 11 geography chapter 4 map projections free pdf, ncert solutions updated as per latest ncert book, ncert solutions for class 11 geography for chapter 4 map projectionsexercise1. This projection uses a combination of the homolographic mollweide 1805 and the sinusoidal variously attributed to mercator, sanson, or flamsteed projections. This model should be more or less spheroid having the length of polar diameter lesser. A conic projection is derived from the projection of the globe onto a cone placed over it. The importance of map projections by sarah lyle on prezi. A type of homolographic map projection in which the surface of the earth is represented as an ellipse, with the equator and parallels of latitude as straight lines. It is the system of transformation of the spherical surface onto a plane surface.
First, that the projection of our map is determined by the order in which we add datasets to the map. It is occasionally used for thematic world maps, and it is combined with the sinusoidal to produce the goode homolosine projection. Theory of map projections is a branch of cartography studying the ways of projecting the curved surface of the earth and other heavenly bodies into the plane. A model of the earth is represented by the help of a reduced scale on a flat sheet of paper. This process is typically, but not necessarily, a mathematical procedure some methods are graphically based. Types of map projections geoinformatics and space technology. Shows size of area relatively well, oval shaped, used to show direction of things, distorts shape and direction.
Practical work in geography class 11 solutions chapter 4. Scale increases perpendicular to the radii toward the periphery. Projection, in cartography, systematic representation on a flat surface of features of a curved surface, as that of the earth. Map projection is the method of transferring the graticule of latitude. However, to maintain accuracy for largerscale maps scales of 1. Homolographic projection definition of homolographic.
Apr 25, 2017 pseudoconic projection is one of the oldest map types and although they were used by ptolemy, they are seldom seen today. What is the importance of map projection in geographic. Homolographic projection definition and meaning collins. Scale distortions on map projections map projections without distortions would represent the correct distance, direction, shapes, and areas on a map. If made smaller, the cone will intersect the earth twice, in which case it is called secant. Type of projection cylindrical in standard presentation, these map regularlyspaced meridians to equally spaced vertical lines, and parallels to horizontal lines. Planar projections are also called azimuthal because every planar projection preserves the property of azimuthality, directions azimuths from one or two points to all other points on the map. Normally it is presented with multiple interruptions. After all, there are many conformal projections, many equalarea projections, and many compromise projections. The next step in choosing a projection is to decide on the class of projection.
Because there is no limit to the number of possible map projections, there can be no comprehensive list. Sep 30, 2016 choosing a map projection the choice of map projection is made to give the most accurate possible representation of the geographic information, given that some distortion is inevitable. There is some info about projections, but more importantly, its about their appearance. The lambert azimuthal equalarea projection is mathematically based on a plane tangent to the earth.
The location shape size of the region to be mapped the theme or purpose of the map 37 38. Direction and shape are good at the equator to about latitude 40 44 n and s. Navigational maps are usually mercator, true direction, andor equidistant. This is a summary of map projections that have articles of their own on wikipedia or that are otherwise notable.
It is perpendicular to the direction of gravity pull. A real geogeek should be able to answer most of these questions. Babinet, elliptical, homalographic, homolographic pseudocylindrical. Mollweide created this pseudo cylindrical projection in 1805. If the cone touches the earth at just one particular parallel of latitude, it is called tangent. These types of maps try to depict the continents as accurately as possible by leaving blank space in the less important areas of the map, such as in the oceans. Only when the voyages of exploration stimulated production of maps showing entire oceans, hemispheres, and the whole earth did the question of projection.
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