2) Make sure that the georeferencing extension is on by right-clicking in the task bar area and selecting Georeferencing

Transcription

1 HGIS Workshop Module 1 Georeferencing Large Scale Scanned Historical Maps Objective: Learn the Principles of Georeferencing 1) In ArcMap, open the project 01 data\arcdata_10_1\arcdata\toronto\georeference.mxd 2) Make sure that the georeferencing extension is on by right-clicking in the task bar area and selecting Georeferencing

2 3) Using the Georeferencing tool, select Layer: 004.jpg and under the menu Georeferencing, select Fit to Display and make sure that Auto Adjust is clicked on. 4) You will notice that the image 004.jpg now appears. This map is a 1910 Charles E. Goad Fire Insurance Plan. This is not a georeferenced image, but simply a scanned image of a paper map. 5) Select the Rotate tool and manipulate the image using your mouse so that the roads on the image are parallel to the roads in your GIS. 6) Your screen should look something like this image below.

3 7) Select the Control Points tool 8) Select the middle of the intersection of Avenue and Davenport on the image (raster file to vector file) and click once. Drag the mouse to the same location on the vector file at the intersection of Avenue and Davenport. 9) You will notice the image has now moved over slightly. Repeat this operation for the Bedford Road and Bernard Street intersection and then the Elgin and Bedford intersection.

4 10) As the last point, you should choose the Avenue Road and Elgin intersection. Your image should now be completely georeferenced 11) If your image is not matching the streets as you would like, you can eliminate some points by selecting the View Link Table icon: 12) If you need to delete a point, highlight it and press the delete key. Click on OK when done and resume adding control points to your image. Note that you should also save your control points. These can be useful later in your work if you need to georeference an image again, or if you want to document your results. Once saved, the control points can be reloaded along with your non-georeferenced original image.

5 13) Once you are content with your image fit in your GIS, there are two options to finalize the images as georeferenced datasets. The first is to Update georeferencing, and the second is to rectify the image. Using the menu from the georeferencing window, select Update Georeferencing 14) Navigate to where 004.jpg is held. What do you notice? 15) This image could now be used as is inside your GIS. You could load this one and many other images together to form a mosaic. But we are still using our original image and it is not truly geopositioned yet.add another Ground Control Point to your image. 16) As a second method for georeferencing your image, use the Georeferencing menu again, but this time select Rectifiy This will create a new rectified or warped images.

6 17) In the pop-up box that appears, select the browse option. Make sure you save the new rectified image in the \01 data\arcdata_10_1\arcdata\toronto\ folder. You can give your new image any name you wish. Select TIFF or JPEG as your image Format: Click on OK. Please note that the default in ArcGIS 10 is to save in geodatabase format. You must select an output location outside of the geodatabase in order to save in TIF or other image format. Ensure that NoData is set at 255 or ) Remove the image 004.jpg from the table of contents 19) Now insert your new rectified image into your workspace using the Add Data tool (\01 data\arcdata_10_1\arcdata\toronto\rectify0041.tif) 20) Navigate to the location where you saved your rectified image. What do you notice about your new image? 21) Georeference this image: CityToronto&Liberties-TPL-MsX1918BW.bmp

7 Using the streets layer tostreets.shp found in the following folder \01 data\arcdata_10_1\arcdata_10_1\arcdata\toronto Discussion: What are the difficulties in georeferencing the image? HGIS Workshop Module 2 Creating your own polygon shapefile Objective: learn to use the Edit functions of a GIS to create new georeferenced layers 1) In ArcMap, open up ArcCatalog by clicking on the Windows menu and then Catalog 2) Select the location for a new shapefile by clicking/highlighting the folder where you would like to save your new shapefile. 3) In this case, save your file under \01 data\arcdata10_1\arcdata\toronto\ 4) Right-click on the Toronto Directory, select New and then shapefile

8 5) Give your new shapefile the Name: buildings and select the feature type Polygon 6) Select Edit and as in module 3, search for UTM zone 17 (this means your datum is NAD83, and UTM Zone 17 is the coordinate system). 7) Click on OK 8) Go back to ArcMap and using File->Open, open the project file \01 data\arcdata_10_1\arcdata\toronto\buildings_10_1.mxd. When asked whether to save the changes, say No. 9) Add your new shapefile: c:\arcgis\data\toronto\buildings.shp 10) Edit your shapefile by clicking on the Editor taskbar and select Start Editing 11) You may get a warning box appearing stating that the coordinates systems do not match. Click Continue to start editing nonetheless.

9 12) The Create Features menu will appear on the right hand side. Click buildings and notice below Construction Tools appear (if you cannot see it, click on this button in the Editor toolbar. 13) Click on the Polygon under Construction Tools then start by drawing a polygon over the Robarts library building. To begin start at one corner and click, drag the line to the next corner and click again 14) Use several points to draw the building, once you are done, double-click on your last point.

10 15) If dissatisfied with your drawing, click on delete, if satisfied, click on the Editor menu and click on Save Edits 16) Zoom into smaller buildings and repeat steps 11 to 13 for two or three more buildings. 17) Save your edits every time your finish a building. 18) Once done drawing, using the Editor menu, click on Stop Editing 19) Answer Yes to save your edits. 20) Right-click on your buildings layer and select Open Attribute Table. 21) Using the Tables Option tab, select Add Field

11 22) Give your field the name name. Make type text and length 50 the default. Click on OK. 23) Leave the Attribute Table open. Under Editor, select Start Editing 24) In the new field of your Attribute Table, start giving your buildings names 25) Once you have entered the building names, click on Stop Editing from the Editor taskbar, and close the Attribute Table. 26) Using the information tool, click on some of the buildings you drew. 27) Repeat this entire module starting at but using a different feature class in ArcCatalog (ie. point, line, etc) to draw roads, or represent trees, etc.

12 HGIS Workshop Module 3 Advanced Editing Using the new georeferenced image from Module 1, create a new buildings shapefile based on that image. Issues: Dealing with topology. Before you start, have a look at this image: 4.jpg Discussion: What are some of the types of information your data could contain? Module 4 Georeferencing Small Scale Scanned Maps Download the following map 5.jpg Issues: dealing with precision; data scarcity Module 5 Georeferencing/Overlaying Scanned Maps in Google Earth Pro Module 6 Building Data from Georeferenced Maps in Google Earth Pro Module 7 Animating historical data in ArcMap Module 8 Animating historical data in Google Earth Module 9 Using ArcScan to Automate Data Creation from Scanned and Georeferenced Maps Download image CityToronto&Liberties-TPL-MsX1918BW.bmp