Digitizing Historic Maps
A step-by-step guide to building interactive historic maps using QGIS, ArcGIS Pro and ArcGIS Online
Geo-referencing in QGIS
1. Select "Raster" from the menu bar and click "Georeferencer"
2. Click on the blue grid icon in the upper right corner of the pop-up, select the raster image that you want to geo reference, then click "Open"
2. To begin geo referencing, click the grey icon with the yellow plus sign along the top tool bar. Now click any point on your image that you want to geo reference. Select "From Map Canvas" and select the point on your base map that equates to the point you clicked on your image. When you are finished, click "OK"
3. When you have your desired number of reference points, click on the green play button in the top right of the tool bar
4. After clicking play, you should receive a message to alter the settings. Select "Thin Plate Spline" for "Transformation Type" and be sure the check that the projection matches your map. Select the three dots next to "Output Raster" and title your layer. When you are finished, click "OK"
5. Save your map layers as a GeoTIF by right clicking on your layer --> click "Export" --> click "Save As"
6. Open ArcGIS Pro and add your GeoTIF layer by selecting the "Map" tab --> click "Add Data" -->click "Data" --> add your GeoTIF layer
-->Follow steps 6-8 in the "Geo-referencing in ArcGIS Pro" section below to add your geo-referenced layer into ArcGIS Online
Adding a Basemap in QGIS
Geo-referencing in ArcGIS Pro
1. Open ArcGIS Pro and add your raster layer by selecting the "Map" tab --> click "Add Data" -->click "Data" --> add your image layer
2. Select the "Imagery" tab and click "Georeference"
3. Zoom on the base map to the area where you want your image layer to be and then click "Fit to Display". This will move your image layer to its approximate real location to make it easier to georeference.
4. To begin georeferencing, click "Add Control Points". Now click any point on your image that you want to geo reference. Turn your image layer off and now and select the point on your base map that equates to the point you clicked on your image. Repeat this step until you have at least 10 control points and your image layer matches the base map to the best of your ability.
5. Select "Spline" and your Transformation type. When you are finished adding control points, click "Save" and then click "Close Transformation"
6. Select your map layer --> click "Sharing" --> Select "Share As Web Layer"
7. Under the "Share As Web Layer" that pops up, name your layer and add a tag. Select "Tile" under "Layer Type." When you are finished, click "Publish" and wait for it to load. When it is finished publishing, you will receive a pop up notification.
8. Open a new map in ArcGIS online then click "Add" --> click"Search for Layers" --> Add your map layer to you map.
Creating Features Layers in ArcGIS Online
** Note that these steps are in MapViewer Classic so your screen may look different when you open ArcGIS online. You can switch between MapViewer Classic and New Map Viewer easily with the tab in the upper right corner of your screen.
1. Click on "Content" --> "My Content" --> "Create" --> "Feature Layer"
2. Search for "Points, lines and polygons" in the search bar. Click on the template that comes up and then click "create."
3. Select your feature type and click "Next."
4. Zoom to your map extent and click "Next."
5. Title your layer and click "Done." Add lots of tags and a descriptive summary here! This will help you organize and fins your data more easily later.
6. To add your new feature layer to your map, open your map and click "Add" --> "Search for Layers" --> "[insert your layer name here]" --> "+"
Customizing your Feature Layer in ArcGIS Online
** Note that these steps are in MapViewer Classic.
1. Select the three dots under your feature layers to see the pop-up options and then select "Show Item Details."
2. Select "Data" --> "Fields" --> "+ Add"
3.Title your field and then click "Add New Field"
4. To differentiate your line features... first select the field that you just created.
5. Click "Edit" next to "List of Values"
6. Add a value for each type of feature you have. For example, add a value for your post road and one for your cart roads. When you are finished, click "Save"
7. To visually differentiate these feature values, go back to your map and select the symbology tab under your feature layer.
8. Under "Choose an attribute to show" select the field that you created with the values, then click "Options" under "Types (Unique symbols)"
9. Edit the different types of features by selecting their corresponding. symbols to change the color and size. Here you can also change the transparency with the sliding bar at the bottom. When you are finished editing symbology, click "OK"
Adding features to the map in ArcGIS Online
** Note that these steps are in MapViewer Classic.
** Don't forget to click "Save "often**
1. To add features to your map, click "edit" --> select the feature you wish to draw --> begin editing by clicking on the map along where you want to draw --> double click to finish drawing.
Adding a Text Pop-up in ArcGIS Online
** Note that these steps are in MapViewer Classic.
1. Go back to the item details for your feature layer and add a new field to "Line Features" the same way you added the "Post Road Field." Increase the String length to at least the number of characters you wish to type in your pop-up. When you are finished, click "Add New Field"
2. Go back to your map and under "Details" then select the three dots to open additional options and click "Configure Pop-up"
3. Here you can edit all of the Pop-up settings such as what you see and what is hidden when you click on a feature. To add a field for you text, select "A description from one field" and under "display" and select your new field name, in this case "Transcribed Text." When you are finished, click "OK"
4. To add your type your text into the pop-up, click on your desired feature, click "edit" and add your text to the box at the top. When you are finished, click "Close."
Adding Labels in ArcGIS Online
** Note that these steps are in MapViewer Classic.
