Q: How do I show lines of latitude and longitude for reference on my coverage map?

A: The TAP Map Window Control form includes several buttons for adding various features to a Map Window. (Note that the Map Window Control form is only displayed when a Map Window is displayed.) This tutorial uses a Map Window showing the CO.BNA boundary file of Colorado counties.

The "Lat/Lon" button enables you to specify and display the lines of latitude and/or longitude to the map:

Click the "Lat/Lon" button, and the Lat/Lon Properties form is displayed:

For both latitude and longitude you can specify major and/or minor lines. Typically, the "Major" lines can be the integer degree lines, and the "Minor" lines are a smaller subdivision, such as .5 degree, .25 degree, .125 degree (= 7- 1/2 minutes). For this tutorial, set the "Major Step" to one degree, and the "Minor Step" to 0.5 degree.

For this tutorial, check the "Major" and "Minor" boxes for both latitude and longitude:

The default ranges ("From" and "To") are based on the currently displayed map area. You can change the values, but for this tutorial, use the default values. (Note that west longitudes and south latitudes are negative values.)

To set the properties (color, line width, etc.) for each line, double click on the line on the form:

The Layer Properties form will be displayed. You can select the properties from this form for each of the line categories. When finished, click the "Close" button.

When the line properties are set, click the "Continue" button on the Lat/Lon Properties form:

The lines will be displayed on the Map Window:

To remove the latitude and longitude lines, click the "Lat/Lon" button on the Map Window Control form.

The lines and text will be removed from the drawing. If you do not want to add lines again, click the "Cancel" button on the Lat/Lon Properties form:

Note that the removal of the lines may leave parts of the drawing missing. You can use the "Redraw" button on the Map Window Control form to repair the drawing.