The shape of the earth and the geodetic datum concept are covered on pages 46. Map projections are ways of transferring information from a 3d sphere the globe to a 2d plane a piece of paper or a computer screen. Navigational maps are usually mercator, true direction, andor equidistant. He graduated from the state university of new york at syracuse in may of 1993 with a ph. Description of a method of choosing suitable projections for particular cimal degrees. A map projection systematically projects locations from the surface of a spheroid to representative positions on a flat surface using mathematical. It is impossible to have a constant scale in different areas of a map but we can get close map has fixed scale but gis is scaleless, i. Projection system in gis pdf the subjects of coordinate systems and map projections are treated under three.
Gis map projections muhammd bilal saleem session 20122014 m. Because maps are flat, some of the simplest projections are made onto geometric shapes that can be flattened without stretching their surfaces. Dana tomlin in his book entitled geographic information systems and cartographic modeling tomlin, 1990. Gis highvoltage gas insulated switchgear substations. Energy information administrations eia interactive u. The california energy commission develops and maintains maps and geospatial information on californias energy infrastructure and related activities. Many map projections are designed for specific purposes. Geographic information systems stack exchange is a question and answer site for cartographers, geographers and gis professionals. This means we have to choose an appropriate projection method and case for our subject area. Gis technology originated in japan, where there was a substantial need to develop technology to make substations as compact as possible. This mathematical transformation is commonly referred to as a map projection. What is the importance of map projection in geographic. As implemented in geographic information systems, projections are transformations from spherical coordinates to xy coordinates systems and transformations from one xy coordinate system to another. This lab activity will give you a chance to work with various forms of base map data, particularly imagery and elevation models.
Browse other questions tagged java gis mapprojections proj or ask your own. After watching this video, you will be able to explain what a map projection is, what a map scale is, and why they need to be carefully chosen when creating a map. Faculty of natural resources management lakehead university the two main reasons why map projections are needed. It can include transmission, subtransmission and distribution networks in the same electrical model and solve the combined networks. Complete with fullcolor maps and diagrams, this book presents practical techniques on how to identify data projections, create custom projections to align data. Selecting an appropriate map projection is one of the first important decisions when working and mapping out gis data.
Invented in the 16th century, the projection is that of the sphere on a cylinder tangent to the equator. Factory portrait savli, india high voltage gasinsulated switchgear and hybrid switchgear, pass engelska pdf broschyr integrated gis technology up to 170 kv modular switchgear in prefabricated housing engelska pdf broschyr maintenance of circuitbreaker sn, high voltage gis elk1, elk2, elk3 engelska pdf broschyr. Although the earth is best represented by a spheroid, the earth is sometimes treated as a sphere. Projections are chosen based on the needs of the map or data analysis and on the area of the world.
All map projections distort the surface in some fashion. Introduction the energy management system ems is employed in electrical utilities for monitoring, control, and data analysis to ensure high reliability of grid operations. Keywordsvisualization, gis, map, power, reliability index, situational awareness, future, forecast, weather, violation, overload. Learn the latest gis technology through free live training seminars, selfpaced courses, or classes taught by esri experts. Map projections are introduced on pages 1012, and pages.
Users cope with these limitations by using map projections that fit their intended uses, geographic location, and extent. Therefore we must use a projection and none are really true to the actual spherical location. He started his career in the gis division of consolidated engineering company in beirut lebanon in july of 1993 as a gis analyst. This public information is accessible through the cloudbased arcgis hub, arcgis online, pdf maps, and interactive web maps links below. Energy maps of california california energy commission. Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the. Soubra is a professional in the geographic information system gis field. Conversion between different map projections in java. Simply, it is placing the spherical earth onto a plane flat surface. Abb pioneered high voltage gasinsulated switchgear in the mid1960s. 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.
You need to know that most gis data, especially for washington state, comes in two datums. Map algebra is an analysis language based loosely on the map algebra concepts presented by dr. A map projection is a method for taking the curved surface of the earth and displaying it on something flat, like a computer screen or a piece of paper. 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. Once a reference datum has been determined the elevation of any point can be accurately determined, and it will correlate to the elevation of any point on the earths surface that has the same elevation and is using the same datum. Only the tm and utm projections are considered in this paper. It is perpendicular to the direction of gravity pull. Within arcgis, every dataset has a coordinate system, which is used to integrate it with other geographic data layers within a common coordinate framework such as a map. Use equal area projections for thematic or distribution maps. Selecting map projections in minimizing area distortions in gis applications article pdf available in sensors 812 december 2008 with 327 reads how we measure reads.
Resources are available for professionals, educators, and students. The links below will take you from the cec web site. Once you have a map file created in gis with all the desired layers, you can export your data in a variety of ways. Etap gis provides owners, operators, and planners geospatial tools to better design, analyze, and expand their networks. One easy way to understand how map projections alter spatial properties is to visualize shining a light through the earth onto a surface, called the projection surface.
Page 79 discuss map scale and the basics of coordinate systems. Secant projections, compared to tangent projections, result in increased low and decreased high. In reality once you decided which projection you are going to work with, to have all your data with the same projection or to transform data that is in another. Maps were devised because they are much easier to use, store, and transport than globes, and they facilitated the development of much larger.
These concepts are discussed on the web page, geographic coordinate systems and. The following concepts are fundamental to understanding the use of map projections in arcgis. Handbook on geographic information systems and digital. Lecture 2 map projections and gis coordinate systems. Gis software also can transform information between coordinate systems to support integration and critical workflows. What is a map projection map projection definition. 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. Presentation maps are usually conformal projections, although compromise and equal area projections can also be used. A guide to map projections is an easytonavigate troubleshooting reference for any gis user with the common problem of data misalignment. Map makers have devised methods for taking points on the curved surface of the earth and projecting them onto a flat surface. Gis for electric geographic information systems map etap. Understanding map projections is important to anyone working with gis because a three dimensional object cannot be represented perfectly in two dimensions.
The geoid is defined as the surface of the earths gravity field, which is approximately the same as mean sea level. Pdf gis uhf partial discharge online monitoring device. Hello guys, today i was explaining somebody about the consequences of messing up the geographic coordinate systems and projection when you are working with gis data. Coordinate systems enable you to integrate datasets within maps as well as to perform various integrated analytical operations such as overlaying data. You will be managing datums, map projections, and coordinate systems in arcgis pro. This video describes the challenges of different map projections, and the map projection decisions that gis users must make. The importance of the correct use of projections in gis. A map projection systematically projects locations from the surface of a spheroid to representative positions on a flat surface using mathematical algorithms. Maps and map reading are essential skills that all of the armed forces need. Maps and gis data are most often displayed on flat surfaces, be it a paper sheet.
Please note though that the topic of projections is extremely broad, and this article can do no more than touch on a few important topics. To export a pdf file of your map you first need to create a layout similar to an autocad viewport that will show all or a portion of your map. Antiti map projections tn 6 a map is a representation of all or part of the earth drawn on a flat surface at a specific scale. This tutorial is released under the creative commons license. A gas insulated substation gis is a high voltage substation in which the major structures are contained in a sealed environment with sulfur hexafluoride gas as the insulating medium.
Introduction to coordinate systems and projections. When data from different sources need to be combined and then used in a gis. The map projection selection tool was developed to help cartographers pick the best map projection for making maps in a gis software program. However, if we go too far from the scale at which map was made before it. Does eia publish the location of electric power plants and. Optimum routing of distribution system network using gis. Description two dimensional representation of the three dimensional earth systematic transformation of latitudes and longitudes to parallels and meridians respectively an intriguing component of the coordinate system. Some common examples are cones, cylinders, and planes. The second chapter discusses, inter alia, costbenefit analysis of an investment in digital cartography and gis, plans for census cartographic process, digital map database development, quality assurance, database maintenance, and use of gis during census enumeration. In doing so, you will become familiar with the study area we will be using for the rest of thesemester. This video describes the advantages and disadvantages of different map projections, and the map projection decisions that gis users must make. Whether you treat the earth as a sphereor a spheroid,you must transform its threedimensional surface to create a flat map sheet. The surface of a sphere cannot be represented as a flat map.