How To: Digitize in ArcView
Digitizing data into ArcView falls into two areas: projected and unprojected
(Geographic). Geographic uses the Decimal degree coordinate system and is the only type of data that ArcView GIS 3.0 can project into another projection.
All sample data included with ArcView is in this format.
With this in mind you will usually want to have the data digitized as
Geographic so it can be overlayed with the sample data included with ArcView
and be projected in a view to another projection. You will only want to
digitize your data as projected if the data it is to overlay is projected.
Themes must be in the same projection in order to overlay in ArcView.
When digitizing in ArcView, if the views projection properties are set to that
of the paper map being digitized, ArcView will convert the shape file as it is
digitized into the Geographic coordinate system. This shape file will only
overlay with data in a Geographic format, but can be projected using the view
properties in ArcView. If the views projection properties are left alone, the
resulting shape file will be left in the projection it is in on the paper map,
and it will also only overlay with data that is stored in the same projection.
It can not be projected in ArcView since this will double project the data,
once by the data itself being stored as projected and once by ArcView using the
Dataset: NAD 27, Arizona, West
To have the resulting shape file in Geographic format:
1. Start ArcView.
2. Load digitizer extension (if not already loaded).
3. Add a View.
4. Set View Properties:
Projection - State Plane - 1927,Arizona, West
Map Units - feet
5. Select 'Digitizer Setup' from the 'View' menu.
6. Change the 'Units' to feet.
7. Use the digitizer's puck to click on atleast 4 tic points of paper map
8. Enter x,y coordinate of each tic using the feet readings on the map.
9. Press the 'register' button when it becomes active or adjust the 'Error
Limit' to make it active.
10. Select 'New Theme' from the 'View' Menu.
11. Choose the type of shape file to create and save it on your hard disk.
12. Use the mouse to select the appropriate drawing tool on the toolbar.
13. Move the puck and make sure you are getting coordinate readings on the
bottom left of ArcView.
If not, press the 'F2' key on your keyboard until you do get them when the puck is moved.
14. Use the puck's left-click button and click in the upper left of the board
and the left double-click button to click in the lower right.
15. Use the mouse and press the 'Zoom to Active Theme(s)' button. You now see the points, line, or polygon you digitized in the area your digitizer is registered to, and your puck should move in an absolute mode on screen.
16. Delete the temporary features in this theme.
17. Start digitizing features into this theme.
18. To have the resulting shape file in NAD 27, Arizona, West:
2. Load digitizer extensions, if not already loaded.
3. Add a view.
4. Click View > Properties and set Map Units to feet.
5. Select Digitizer Setup from the View menu.
6. Use the puck to click four or more tic points of a paper map.
7. Enter x,y coordinates of each tic using the feet readings on the map.
8. Click Save and save the tics to a text file.
9. To activate, click Register or adjust Error Limit.
10. Add the saved tic file as a table in Arcview.
11. Click View > Add Event Theme and select the tic file table as an XY event theme.
12. Turn on the theme and you will see the tics from the paper map.
13. The puck should now move in an absolute mode when inside the area outlined by the tics. If it is moving like a mouse, press the 'F2' key to toggle into puck mode. Puck mode displays the coordinate readings on the bottom left corner of ArcView.
14. Select New Theme from the View menu.
15. Select a shape file and Save.
16. Select the appropriate drawing tool and begin digitizing.