Digitizing Your Map with ArcView

Preparing the base map:

Before any digitizing can occur the base map must be prepared. All geological contacts should be drawn, all faults should be drawn, etc. The base map should be clean and crisp. If it is wrinkled or has been folded this can cause problems while digitizing if you can't keep the map taped flat too the digitizing board. If you wish to be extremely precise the base map should be drawn on mylar because it doesn't contract and expand as much as regular paper will.
The next step is too locate and mark on your map at least four points that you will use as a control point for registering your map. These points may be anywhere you wish and you may have more than four (supposedly the more control points you have the more accurate your digitizing will be). Choose points that are easily recognized such as the intersections of roads or streams and mark these points on your map. Label each control point with a number (i.e. 1,2,3,4).

Preparing ArcView:

Start ArcView and open a new view. Do not add any themes too your view at this point. Go too the View menu on the top and choose properties.In the View Properties Box you now see you can rename View1 to something else if you prefer.Under the creator box you may also fill in your own name. Now choose projection and then under category choose UTM and under type choose Zone 13. Then press ok to exit the Projection Properties Box. Under the Distance Units select units of distance that you like (i.e. miles, kilometers, inches, whatever) and then click ok again to exit the View Properties Box.

Find geographic coordinates of control points:

If you are using the aerial photographs of the Slim Buttes as your base map you should now load the air photo tiff file that is on the computer. If you used the topographic map as your base map you should load that instead. For whichever image you are using, as you're base map find the points on the screen that you marked on your base map for control points.
Note that in the upper right hand corner of the screen there are two numbers that change as you move your mouse over the screen. The top number is the coordinate for the x-plane and the bottom number is the coordinate for the y-plane. Place your mouse cursor exactly over each of your control points and write down the coordinates for each one.

Setting up the Digitizer:

As of right now the digitizer should work without you having to do anything too it. If you go through the next steps and are completely unable to make the digitizer work go through the Digitizer Set Up procedure as posted on the wall by the digitizer.

Register your Map:

Tape your map using drafting tape too the digitizer board. Keep the map away from the edge of the board; you should be at least four inches from the bottom or the side of the board. Make sure that your map is flat and will not move once you start digitizing. Don’t worry about aligning the map precisely on your tablet. ArcView corrects any alignment problems when you register the map and tells you about such adjustments in the error report.
Now go too Digitizer Setup under the View menu. You will see in the upper left hand side of the Digitizer Setup box it says decimal deg, click on this box and switch from decimal deg too meters.
 

Now take the digitizer puck (the little thing with the keypad that’s attached too the digitizer) and move the puck across the board. Before you digitize your control points look back too the Digitizer Setup Box, you should see on the top a little white box with an x-y plane drawn on it and numbers on the sides of the box. If the numbers change as you move the puck across the board you're set too go, if not press the F2 key. If you still don't see any numbers use the mouse too select the puck icon (there are two graphics on the top right hand side of the Digitizer Setup Box, the one on the left is the mouse and the one on the right is the puck icon). If you still do not see any numbers exit the Digitizer Setup Box and go through the Digitizer Setup Procedure and then go back too the Digitizer Setup Box. If after having gone through all this and still nothing happens try restarting ArcView or the computer.

Assuming that everything is working center the cross hairs of the puck over your first control point and press the "0" key once on the puck. You should see a "1" appear in the table. Now digitize each of your remaining control points. Make sure you have these points selected so that you can place the cross hairs exactly in the same place again if you need to re-register your map in the future.

With all of your control points digitized you must now enter in the coordinates for each one of your control points. The first column too the right of the control point number is for your x-coordinates and the second column is for the y-coordinates. The third column will give you the amount of error once you have entered the coordinates for at least four control points. Go through the table and enter the coordinates for each control point and press enter after the last point is done. Once you specify the true coordinate location for a control point, ArcView adds a mark (asterisk) at the beginning of the row indicating that the control point has been entered and its ground coordinates are now know.

Look n the bottom right hand corner of the Digitizer Setup Box, if the Register button is highlighted so that you can register the map your in good shape. If the Register button is still greyed out though you have too either re-digitize your control points or you have to play with the error value box. In the error box the default value is 0.004 inches but you can change this. Look at the error column in your control points and enter a value that is slightly higher than these. Keep increasing the number till it will allow you to register. If you have to raise the error value above 0.008 inches you should consider rechecking your coordinates and or re-digitizing your control points.

If you were fortunate and the Register button was set too go without increasing the error value you should try to decrease the number to insure as small of an error value as possible.

Once the error value has been set and the Register button is highlighted you are set to go. But before you press that Register button press the save button. This creates a tic file that will allow you to reregister your map should you not finish digitizing it in one sitting.

After the tic file has been saved you may now press the Register button.

Registering the map from a tic file:

If you need to quit digitizing before finishing your map you will need to reregister your map the next time you work on it. Go through all of the steps for preparing ArcView as you did before and then go too the Digitizer Setup box. Press the load button and load your tic file. You should now see your control points and their true coordinates listed on the table as before. Now take the puck and in the exact order you digitized your control points the first time digitize your control points on the base map again. You may have a better or worse error value then your previous session with ArcView and you will have too play with it some. Once the error value has been set press the Register button and continue digitizing from where you left off. Again it does not matter if the map is not taped in the exact same location on the board, as it was the first time.

Digitizing your stuff:

Go to the View menu and choose New Theme. For the feature choose a polygon and name it outline or something else if you prefer. Click on the rectangle drawing tool and center the cross hairs of the puck on one corner of your map and press the "0" key once. Now move the puck too the opposite corner of your map and press the "0" key once. Now choose the Zoom too Theme option and you should see a large rectangle. You may keep this as the border for your map or delete it if you wish. The only reason for drawing this is too zoom too a scale where you can see your project.
Create new themes for each feature you wish to digitize… For lines or polygons that have irregular boundaries (i.e. streams, formation contacts, etc) you may wish to use the stream digitizing feature that allows you to simply trace the line from your map onto the screen. To enter or leave this mode simply press the "F3" key. If you do not use stream digitizing you will have to move the puck and enter each point manually.
 
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