Creating a Map with ArcMap - Tufts University

scale, you must be aware of the coordinate system and map units. These are accessible in the data frame
properties. You can also give a name to a data frame (right now your data frame is called "Layers").
Accessing the Data Frame Properties
• To access the data frame properties, right-click on the word "Layers" at the top of your Table of
Contents and choose Properties.
• Click on the General tab.
• For Name, type in a name for your map (e.g., Someverville)
• Note that for Units, the Map Units are likely designated as feet (grayed out) and the Display units
are also set to feet (if you added the MassGIS data first, it might say meters). The Map Units are
the actual units of the coordinate system in use - you cannot change these. The Display units can
be changed - these are what appear if you measure distance on the map or are the default units for
a scale when you create a map layout. Don't change the map units and return to your map.
• Click on the Measure tool ( ) in the Tools toolbar. Click somewhere on the map to start a
measuring line. Drag the line somewhere else and click again. You will see two measurements
reported in the Measurement window. The first, segment, gives the distance (in Display units) of
the line you just drew. The second, Length, gives the total distance. Click on a third point in the
map. You will see the new segment distance plus the total distance of both segments. Double-click
on the map to stop measuring (or choose a different tool).
• Try changing the Display Units in the Data Frame properties (e.g., to miles) and use the measure
tool again to see your measurements in your chosen units.
• Go back to the Data Frame properties (right-click on the data frame name at the top of the table of
contents).
• Click on the Coordinate System tab - you will see that the data is most likely in the
NAD_1983_StatePlane_Massachusetts_Mainland_FIPS_200_Feet1 coordinate system. Don't
change anything here right now. We will discuss coordinate systems more in class because they
are very important and can cause a lot of problems. But this is where you check or change
coordinate systems of a data frame. Return to your map now.
Drawing a map to scale
• As long as the data frame has a known coordinate system, you can draw a map to scale by setting
the scale in the scale area of the Standard toolbar:
• Click on the 1:10,000 scale and view your results. Try other scales. You can also type in a scale
yourself (you only have to type the denominator, e.g., 24000, no commas). These are unitless
scales. 1:24,000 means that one unit on the map (or your computer screen) equals 24,000 of those
same units in the real world. For example, one inch on the map equals 24,000 inches in the real
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