Mapping Center

How fast can you cache?  We keep asking ourselves that and keep finding that the more we know the faster we cache.

If you’re involved in the job of caching maps for online map services, you are already familiar with the need to optimize the process as much as possible so that it takes less time and effort. One way you can do this is to optimize how your maps are displayed – another is to optimize the environment you are caching your map in or the circumstances under which you are caching. This blog post is dedicated to the latter. Read More...

As you zoom in (or out) of the online maps you see on Virtual Earth (VE) or Google Maps (GM), you are actually seeing a series of different maps with slightly different information displayed at each zoom level. Zoom level is indicated and controlled in an online map by the vertical zoom slider, like the one shown at the left in the image here. Whenever the zoom level is changed, a different map is shown.

Of course, these maps are well designed so that viewers are largely unaware that they are seeing these different maps. The foundation for good design of an “online map” hinges on understanding how to design for each of the zoom level represented in the entire online map. Colors, fonts, number of and types of features, etc. are all seriously considered when each of the maps is created for each of the zoom levels. Read More...

When cartographers talk about "optimizing a computer display", they're usually talking about how to see things better, i.e., remove fuzziness, ensure all the information is shown, etc. This contrasts with how computer technology folks use the term "optimize", which usually means make the screen display draw faster. Read More...

Yesterday I got an email from a long time colleague showing me an online map and asking, “When will it be possible to do this map with ArcGIS”? The map is the interactive map of Washington DC at http://dc.everyblock.com. In particular my friend was looking at the crime map wondering how the proportional symbols showing crimes became disaggregated as he zoomed in, eventually showing individual crime sites. Read More...

This final part of the series will cover using cartographic representations for dashed lines, like the red and white cased lines in the image at the left, and for creating cul-de-sac or squared off ends to streets.  Both of these effects will build on the examples in the previous two portions of this series with one exception.  Because we will be using cartographic representations for the streets, we will be better able to manage line caps and therefore will not need to use the Dissolve tool to dissolve the streets by name, type, and z-level.  The removal of this step is significant because now an extra dataset is not required just to have cartographic quality streets; everything needed for a high quality cartographic depiction of streets can be stored in attributes. This should come as good news to those of you who have mentioned to us, many times, that managing additional datasets for the sake of cartography is not only a data management, but a political hurdle, that you would just as soon not have to deal with. Read More...

Exporting to an external graphics package like Adobe Illustrator or Macromedia Freehand from the ArcMap environment can have its challenges. One positive aspect of exporting is the ability to make certain that CMYK values are retained for proper print color reproduction. Some of the challenges you may face after export are inconsistent vector line widths, irregular polygon shapes, and something our programmers call polygon dicing. Read More...

For many GIS users and cartographers, the use of external graphics software is a common step in his or her workflow and production of print quality maps. One of ArcMap's more popular export formats is the Adobe Illustrator (AI) export because of its wide compatibility with a number of graphics software packages. This export format was first made available in ArcGIS 8.1 Service Pack 1 and has been popular ever since. The ArcMap AI exporter has been fully tested to work in Adobe Illustrator CS and CS2. It is currently being tested in CS3 with good initial results. Read More...