A geographic information system (GIS) is a collection of hardware,
software, geographicdata, and personnel designed to create, store, edit,
manipulate, analyze and display geographically referenced information.
EXPLORING ARCGISCONTENTS1. GEOREFERENCING OF TOPOSHEET 9
INTRODUCTION TO ARCGISA geographic information system (GIS) is a collection of hardware,software, geographicdata, and personnel designed to create, store, edit,manipulate, analyze and display geographically referenced information.ARCGIS DESKTOP SOFTWARE SUITEArcGIS Desktop is accessed using one of three software licenses withvarying levels of functionality:ArcView - provides comprehensive mapping and analysis tools withsimple editing and geoprocessing capabilitiesArcEditor - provides all ArcView functions + advanced editingcapabilitiesArcInfo - provides all ArcEditor functions + advanced geoprocessingand datamanagement toolsAPPLICATIONSArcGIS Desktop includes two main applications: ArcCatalog and ArcMap.ArcCatalog - used to organize and manage your GIS data. It also allowsyou to previewdatasets and view and manage metadata.ArcMap - used to view, edit, and analyze spatial data and create maps.ArcScene - ArcScene provides the interface for viewing multiple layers of3D data, visualizing 3D data on a 2D surface data, creating 3D surfaces,analyzing 3D surfacesArcToolbox is a component of ArcCatalog, ArcMap and ArcScene. Itcontains tools for geoprocessing, data conversion, and defining mapprojections.
EXTENSIONSThe ArcGIS Desktop extensions provide you with additional GISfunctionality. Most extensions are optional products that are registeredor licensed individually. A suite of optional extensions is available forArcGIS Desktop, adding capabilities for raster analysis, three-dimensionalvisualization, advanced map printing, and so on.COMMON TERMINOLOGYPoint: a single location having an X, Y (and sometimes, a Z) position(point features have no area and no length)Line : a series of connecting X, Y positions (line features have length, butno area)Polygon: one or more connecting lines that form a single spatial feature(polygon features have both area and perimeter)Attribute Table: a table (much like a spreadsheet) that containsinformation about, and is linked to, spatial features. Each spatial featurehas one associated record (row) in the attribute tableCOMMON GIS DATA STRUCTURES Vector: In a vector data structure, geographic features (such as wells, roads, national parks, etc.) are represented by points, lines, and polygons that are defined by a set or sets of [X,Y] coordinates. Raster: In a raster data structure, spatial data are stored in a two dimensional matrix, much like a checkerboard. Each raster, or cell, contains a value.USING ARCMAPArcMap is the ArcGIS application that you use to display, query, edit,create, and analyze geographic data.
LAUNCH ARCMAPArcMap can be launched independently or from ArcCatalog. Use one ofthe following methods to launch ArcMap with “A new empty map” now: 1. You may launch ArcMap by clicking Start > Programs > ArcGIS > ArcMap. Whenprompted, select A new empty map. 2. To launch ArcMap from ArcCatalog, click on the ArcMap icon on the standardtoolbar, then select a new empty map.THE ARCMAP INTERFACEKey components of the ArcMap interface are: The title bar, menu bar, and toolbars; Two side-by-side windows: the Table of Contents and the map display window; The status bar.The Title Bar at the top of the ArcMap window displays the name of themap document.The Menu Bar, located just below the Title Ba contains a series of menuitems: File, Edit, View, Insert, Selection, Tools, Window, and Help. Title bar Menu barClicking on a menu item opens a dropdown menu with numerousoptions. To select an option on the dropdown menu, click and release themouse button on the option.
ArcMap includes a variety of Toolbars. Click on the View menu item andselect Toolbars to see all of the toolbars that are available to you. A checkmark next to the toolbar name indicates that it is visible. For now, besure that the Standard Toolbar and the Tools Toolbar are turned on, asshown below:The Standard Toolbar contains buttons that give you fast and easy accessto many of the Menu Bar options. Click on the button to execute aparticular operation.The Tools Toolbar includes tools that allow you to interact with the datadisplayed in the map display window to carry out specific tasks. Typically,the pointer changes when a tool is used.
ArcMap provides a number of other toolbars, such as:Draw - for drawing graphics and adding textEditor – for editing spatial dataLayout – for working with layoutsEffects – for altering the display of spatial dataYou can access the toolbars list without using the View menu by right-clicking anytoolbar or the statusbar. To quickly hide or turn off a toolbar, click its Close button.The Status Bar, located at the bottom of the ArcMap window, givesinformation about the function of a button or a tool when pointed over it.The status bar also displays the coordinate position of the mouse pointerThe Table of Contents, located on the left side of the ArcMap window,lists all of the layers that you have added to your map and shows thesymbols that are used to represent the features in each data layer. Thecheck box next to each layer name indicates whether it is currentlydisplayed in the map display window to the right of the Table of Contents(i.e., whether it is turned on or turned off). The order of layers within theTable of Contents is also important. Each data layer represents a specifictype of feature such as Boundaries, Villages, Water Bodies, Road, Rail,Power Lines etc.ADD AND REMOVE DATA LAYERSTo illustrate basic features of the ArcMap interface, add a shapefile and aTIFF image to your “new empty” ArcMap map document, as follows:1. Click the Add Data button on the standard toolbar. In the Add Datadialog,navigate to X:Exercise folder, highlight india_ds.shp orindia_raod.shp, and click the Add button. Notice that the respectivedata layer is added to the Layers data frame in the Table of Contents.
2. Use the same procedures to add a Toposheet, DDN_53j16.jpg locatedin X:Exercise2 folder, to your map. For now, click OK to bypass theSpatial Reference warning window that pops up.
3. To remove a data layer, right-click on the name of the layer in theTable of Contents window and select Remove from the context menu thatappears. Pan control Zoom in Zoom out control4. Panning : Panning tool is used to move within data (Left, Right, Up,Down) without changing its extent.5. Zooming : It is used to Zoom In and Zoom Out the image on map.
CHANGING SYMBOLOGICAL LOOK OF THE LAYERSArcMap provides many tools to aid in the display of layers. With thesetools, you can make attractive maps but, more importantly, the toolsallow you to explore and analyze the data in the layer in a wide variety ofways.ArcMap displays the layer using system-defined defaults. However, thesedefaults can be adjusted. An overall color scheme can be selected from aset of predefined color schemes, or the color scheme can be changedinteractively.Select India_St layer, right-click on the layer name in theTable of Contents, and choose Properties at the bottom of the menu.Click the Symbology tab at the top of the dialog window.Select Categories on the left and select Unique values as the Categorytype to display. The Layer Properties window should now look like this:
Under Value Field, use the dropdown list to select the STATE field.Under the Symbol field, uncheck the <all other values> symbol and thenpress the Add All Values button at the bottom of the window area. All ofthe values from the STATE field will be added. The Layer Propertiesdialog should now look like this:
Click OK and view the results in the map display.
DATA VIEW AND LAYOUT VIEWArcMap provides two different ways to view a map: data view and layoutview. Data view is used when you want to browse, edit, and/or analyzethe geographic data on your map.Layout view is used to prepare finished maps for printing, presenting andpublishing maps.To switch between data and layout views:1. Click the View menu item and select either Data View or Layout Viewfrom the context menu that appears.2. Alternatively, you can use the Data View and Layout View buttonslocated in the lower left portion of the view window to switch betweenthese two views.
3. When you switch to Layout View, the Layout toolbar is automaticallyadded to the ArcMap window. These tools allow you to zoom in and out,pan, and zoom to set extentsGeoreferencing of Topo Sheet1. Open Notepad and key in the four corners of the Toposheet (in DegreeDecimal) bas shown below.2. Save the file in the desired folder for e.g. X:Exercise Data with anyname like DDN_53j16.txt3. Then Open Arc Map software.Click on Start -> All Programs -> Arc Gis -> Arc Map4. Click on “A new empty map” as shown below. Then Click OK button.
5. In Arc map window Click on Tools Add XY Data…as shown below.
6. Click on Browse button and add the file created in notepad before asshown below.
Click on Browse button and add the Notepad file created before.7. Then Click on Edit Button to add Co-ordinate system as SpatialReference Properties window opens as shown below.
8. On this window Click on Select Geographic Coordinate Systems Asia Everest - India and Nepal.prj and Click on Add Button.9. The Co-ordinate system is added as shown in above image. Then Clickon Apply-> OK ->OK ->OK button. The Points are plotted in Arc MapWindow as shown below.
10. The Point frame is ready as shown above. But this point file is inGeographic Coordinate System. If you want it to be changed intoProjected Coordinate system follow the steps given below.11. Right Click on Layers in Table of Contents on the Left side of Arc MapWindow. Then Click on Properties…. as shown below.
12. Data Frame Properties window open. Click on Coordinate System Tab.Then Click on New Projected Coordinate System… as shown below.
13. A “New Projected Coordinate System” window opens as shown below.
13 a) Fill the Details as: -• Name – Polyconic• False Easting – 100000• False Northing – 100000• Central Meridian – 72.875• Latitude of Origin – 24.625• Linear Units – meters• Geographic Coordinate System• Click on the Select button :- Browse for Coordinate SystemWindow appears• Select Asia – Everest – India Nepal.prj• Click Add -> Finish.14. To complete the task of converting Geographic to Projected we have to dotransformation. For that click on Transformations... button as shown below.
New15. The Click on New -> OK -> OK -> Apply -> OK. Transformation iscompleted.16. Now your point file has been transformed to Polyconic Coordinatesystem and has to be exported into a shape file.17. Right click in Table of Contents on the point file created.DDN_53j16.txt Events.->Data -> Export Data as shown below.
18. An Export Data window opens as shown below.
19. In this window click on “the data frame” and give the file name andthe desired path as shown above and click OK -> Yes button.20. The file is now added to your Table of Contents as shown below.Remove the old file by Right Click on the old file and click on Remove.21. Now we will add the Toposheet on which Georeferencing has to bedone. Click on Add button in Arc Map window and add the Raster filewhere ever placed in the system.22. For geo-referencing we have to open two toolbars (EDITOR &GEOREFERENCING) for that right click on above side of Arc map windowand switch on the desired toolbar as shown below.
23. Place the toolbars in Arc Map window according to your wish.24. To make the Toposheet visible Click on Georeferencing button -> Fitto display as shown below.
25. The toposheet will get added as shown below.
26. For better accuracy we have to enable Snapping function with thecontrols points file. For that click on Editor button -> Start Editing asshown below.27. Then again click on Editor Button -> Snapping button. A new windowopen in which you have to check on the Vertex for enable editing asshown below Close Vertex Button then Close this snapping toolbar
28. Now as the Snapping is Enabled it will give you better accuracy whileadding link points.29. Click on Add control point button. First place a point on Toposheetand then snap the corresponding point feature.30. Add all the four points and then click on Georeferencing toolbar Recify button as shown below.
31. As you click on Rectify button a new window opens as shown below.32. In this window set the following: Output Location, Name & Format(TIFF) and click on Save button. Leave the rest of the setting as default.33. Your toposheet has been georeferenced.