TO CHANGE THE WORKING PROJECTION SYSTEMS
1 Click “View” at bar menu
2 Data Frame Properties
3 Projected Coordinate Systems
3 UTM
4 Africa
5 Minna UTM Zone 31N
6 Apply & OK (Projection Systems has changed to Minna UTM Zone 31N)
IMPORTING A SCANNED MAP/SATELLITE IMAGERY
1 Click “Add Data”
2 Click “Connect to folder” (at the fourth right sub-menu bar to locate the folder where the Imagery was saved)
3 OK & Add
4 Yes (It will start loading the Imagery at the bottom 1-100%)
5 OK
TO GEOREFERENCE
1 Click Georeferencing
2 Click Fit-To-Display and mark Auto Adjust if it’s not marked
3 Click the “Add Control Points” tool to add control points (You can look for road intersections, land features, building corners, or other identifiable objects and match them in your raster dataset and aligned datasets and zoom to the last extent if possible, depend on the resolution of the imagery)
4 Right click the point and click Input X and Y.
5 Type the reference coordinates on the Enter Coordinates dialog box.
6 Click OK.
7 Click “Full Extent” to bring the imagery back because it will disappear immediately you click OK
Note: A minimum of 4 well distributed points on the imagery is recommended for georeferencing, the more the number of points. The better for accurate georeferencing.
8 Click the View Link Table button to evaluate the transformation.
(You can examine the residual error for each link and the RMS error. If you are satisfied with it)
9 Click Georeferencing and click Update Georeferencing to save the transformation information with the raster dataset.
CREATING A FEATURE LAYER
1. Navigate to the ArcCatalog. Click on the ArcCatalog tool on the tool bar.
2. Click on the directory/folder you intend to save the shapefile that you have created (e.g Akolade ArcMap Tutorial).
3. Right click on an empty space in the view section of the ArcCatalog and select New and scroll down to Shapefile.
4. In the dialog box that appears, enter the name of shapefile (e.g Minor_Roads) and select the kind of feature you intend to create (i.e. Point = Transformer, Polyline = Roads, and Polygon = Buildings).
5. Select the projection in which you want to display the data. To change the projection ( i.e click Edit – Projected Coordinate Systems – UTM – Africa – Minna UTM Zone 31N)
6. Click OK
7. Double click the layer name from the Table of Contents to add the appropriate symbols and colour
Note: ArcMap, AcrCatalog, ArcScene and AcrGlobe, they are all inside the AcrGis
How To Digitize Feature Into Its Respective Layers
1. Click on View Menu – Toolbars – Editor
2. From the Editor Toolbar, Click on Start Editing from the drop down menu
3. Select the Sketch tool and use it to digitize the data.
4. Select task to be carried out from the task drop down menu. E.g. Create New Feature.
5. Select the Target Layer from target drop down e.g. Road
6. At the end of the digitizing exercise, click on Editor Toolbar, Click on Save Edit.
7. Click Editor Toolbar, click Stop Editing.
