Mapping Center

This post, is to announce the release of a map template for historical GIS called Historical GIS:  Boston 1775. If you’ve never given historical GIS a second, or a first thought, you might find the contents interesting and maybe even applicable to your work. Consider that the vast majority of GIS data is historical, even if it’s only a few minutes old. Read More...

One of the most frequently recurring topics on Mapping Center is what to do with stacks or clusters of point features on maps. In August 2007, I wrote a blog posting on how to use Maplex to display coincident points, and this worked for some scenarios, but not all. Read More...

In the United States, the Public Land Survey System (PLSS) is a way of subdividing land. The USGS topographic map symbols for displaying PLSS data are an excellent way to symbolize PLSS data on not only topographic maps, but because the topographic symbols are  so well recognized, the same symbols can be used on many other kinds of maps. In the image to the left, the "plus" marker symbol shows where a found corner is located, however, if no corner has been found, then no marker should be shown, leaving a gap that signifies the doubtful location of the corner. Next we will describe how to use cartographic representations to symbolize township, range, or section lines to leave a gap at the corners, allowing corners to be added (as point features) or gaps to be shown. Read More...

Indicating that a street is one-way and which way is valid to travel was a lot harder than it should have been prior to version 9.2.  At 9.2, the new representations symbology makes this a much faster and easier task.  To create this effect, you will need to have your street line data stored in a geodatabase which is a requirement for using representation symbology.

You will also need to have a field in your data that indicates whether a street is one-way. This also depends on the digitized direction of the street lines to align the arrows in the correct direction. If your streets are not digitized correctly, you can edit them by selecting each feature, set the Edit task to Modify Feature, then right click on the feature and choose Flip. Read More...