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This exercise will briefly introduce you to the methods of inputing geographic data into Arc/Info. Data may be input by drawing with the mouse, by entering geographic coordinates from the keyboard, or by using the digitizing tablet to 'trace' the desired coverage into digital form.

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  Digitizing in ArcEdit

With the exception of the generate command, all digitizing with Arc/Info is done in the ArcEdit sub-program. To get to this sub-program, type arcedit at the arc prompt.
The following is a list of commands that you will need for most digitizing sessions in ArcEdit ... 
NOTE: Additional fields within < > are required, those within {  } are optional.

Arcedit: display   <9999>   {2,3}

• sets the graphic display window. Option 2 or 3 gives different size screens.

Arcedit: create   <out_cover>   {tic_bnd_cover}

• creates a new coverage. If {tic_bnd_cover} is given, an empty coverage is created containing the tics from the specified tic_bnd_cover.

Arcedit: editcover   <cover>

• specifies which coverage will be active for editing.

Arcedit: editfeature   <feature>

• specifies which features will be active for editing (arc, node, label, poly, etc.).

Arcedit: mapextent   <cover>

• draws all coverages to the extent of the cover given. If you were editing a map of the US for example and gave the mapextent as a Utah cover, you would only see that part of the US cover that fell within Utah.

Arcedit: backcoverage   <cover>   {symbol}

• draws the specified cover as a background (that cannot be edited) using the specified color symbol (which is a code from 1-12).

Arcedit: backenvironment   <feature>   {on,off}

• sets the features to be drawn for the backcoverage(s). Feature = all, arc, node, label, etc.

Arcedit: drawenvironment   <feature>   {on,off}

• sets the features to be drawn for the edit coverage. Feature = all, arc, node, label, etc.

Arcedit: image  <image>

• sets the specified image as background.

Arcedit: draw

• draws the edit coverage and all backcoverages that have been specified.

The above commands are used to set up your digitizing session. Once you have your edit coverage and any backcoverages drawn as you've specified, you can start digitizing with the mouse or the digitizing tablet.

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Right Now

Make sure you are in your gis# workspace, then follow through the ArcEdit session below by typing the following commands...
At the Arc prompt, type arcedit you will get an Arcedit prompt, type the following commands as shown ...

 
Arcedit:  display  9999
Arcedit:  editcoverage /auto/tl009/hirolls2
Arcedit:  backcoverage hirolls2

• This tells Arcedit that you want to draw the hirolls coverage as a background coverage.

Arcedit:  backenvironment arc

• This tells Arcedit that you want to see the arcs of all background coverages

Arcedit:  drawenvironment all
Arcedit:  draw

• Roads should be displayed  for the High Rolls image.

Stay in your digitizing session, we will be working more with it in a bit ...

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Right Now

Continue following along by typing the commands below ...
 

Arcedit: editfeature arc

Arcedit: add

• You should get the "add arc" menu mentioned above.

Try adding a few arcs, experiment with the various menu options. With your cursor in the display window, press 9 when you are done adding arcs.

Arcedit:  editfeature point

Arcedit:  add

• You will get the "add point" menu mentioned above.

Add at least 10 points, experiment with the various menu options.

with your cursor in the display window, type 8 (digitizing options) from the keyboard. This will give you a new list of options.

             With your mouse cursor in the display window, Press 9 on the keyboard to quit adding points.

Arcedit:  quit

• to quit ArcEdit (answer Y to save changes)

Once you quit Arcedit, you will return to an Arc prompt. You should now have the coverage named mouse in your workspace that contains several lines and points that you added with the mouse.

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Using the Digitizing Tablet

Digitizing with the tablet is also performed in ArcEdit. You will use the same commands shown above to set up your digitizing session. The only difference is that you will have to coordinate the digitizing tablet to the map you are working on. Below are some additional commands that you will need to do this ...

Arcedit:  digitizer   <95000>   </dev/ttya>

• tells the machine that you will be using the digitizing tablet, not the mouse.

Arcedit:  &station <digitizer>

• sets the display to the largest window, tells the machine that you will be using the digitizing tablet.

Arcedit:  create  <cover>   {tic_cover}

• use create to make a new coverage. When the digitizer is coordinated (digitizer 95000 /dev/ttya), ArcEdit will prompt you to define the coverage's tics.

Arcedit:  coordinate <digitizer>  {cover}

• tells ArcEdit which cover you are going to digitize. You will be prompted for the input of the cover's tics, so that what you input on the tablet will match up correctly with the GIS coverage.

Arcedit:  coordinate   <mouse  |  digitizer>

• switchs back to making the mouse or digitizer active.

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Defining Tics for a New Coverage...

When you create a new coverage to be digitized from the tablet, you will get the following prompt and menu, asking you to define at least 4 tics.

You should find and mark your tic locations on your map before you begin digitizing. Enter tics by placing the crosshairs on the "puck" over the position on the map where you wish to place a tic. First enter the tic # from the keypad (usually, your first tic will be #1, your second #2, etc.), then enter "A" to give the position, and "A" again to enter. When you have entered a minimun of 4 tics, enter "0A" from the puck to indicate you are done entering tics.

Each time you go into ArcEdit to digitize from the tablet, you will be prompted to enter these tics again to register your map to the GIS. Make sure you mark them so you can enter the same locations each time.

Digitizing is performed as with the mouse. Simply type add once your editfeature is specified and you will get one of the following menus ....

Points...

Arcs...

Move your crosshairs over the desired position and enter the appropriate number from the digitizing puck (2 for nodes, 1 for vertices, etc). When you are done adding features, select 9 from the puck to get the arcedit prompt back.

To quit your ArcEdit session, type quit. To quit Arc, type quit again at the arc prompt.

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Assignment

Follow through the following digitizing session using the digitizing tablet and the High Rolls image on the digitizing tablet ...

Arc:  arcedit

Arcedit:  &station dig

• This will set the display and coordinate the digitizer.

Arcedit:  create hr_roads

• You will be prompted to enter at least 4 tics, enter the four tics (circled on the map) as explained above, starting  with the tic labeled "1" and proceed clockwise.
• You will then be prompted to define the map limits. This is done by pressing "1" on the digitizing puck in the far south-west corner of the map and then again in the far north-east.

Arcedit:  editfeature arc

Arcedit:   drawenvironment   all

Arcedit:   draw

Arcedit:  add

• You will get the "add arc" menu mentioned above.
• Press "2" on the puck where you wish to start an arc (from node), press "1" on the puck to add vertices, then press "2" to end the arc (to node). Close polygons by joining from and to nodes.

Digitize the ownership polygons for the portion of Cache County you were assigned. Make sure that everyone in your lab group gets a chance to digitize.

• With the digitizing puck on the tablet, Press "9" when you are done adding arcs.

Arcedit:  quit

• You will be prompted twice if you wish to save the changes to your coverage. Type Y to both, the cover will  be saved and you will get an arc prompt.

Arc:  quit to exit arc.

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Getting back into your digitizing session:

Arc:  arcedit

Arcedit: ec  owner
or whatever the coverage you created is called

Arcedit:  &sta  dig
Arcedit:   drawenvironment    all
Arcedit:   draw
Arcedit:  coord   dig   owner
enter tics,  etc.

 To recieve credit for this portion of the exercise, I will simply check your directory to make sure your group has digitized this map.