In the blog, “A Technical Approach to Large Feature Datasets”, we demonstrated methods to display large amounts of data quickly and without layer drawing errors. Although tools are available to draw a bazillion features quickly on the web, does showing … Continue reading
Introduced with ArcGIS 10.1, Python Add-ins provide the newest mechanism for customizing an ArcGIS Desktop application (e.g., ArcMap). These add-ins take scripting to the next level by providing the ability to incorporate user interface elements (e.g., buttons, tools and toolbars) into the customization. Continue reading
By Kenneth Field, Esri Research Cartographer
When creating a web map using ArcGIS.com Map Viewer, the basic approach involves adding operational overlays to a basemap. As you add layers, they are set by default to be visible at all zoom scales. This often leads to problems at smaller scales as symbols overlap which can very easily render your map illegible and meaningless. By contrast, when you create a static map at a single scale you would consider the available map space and so design and position symbols to avoid these problems. It is useful to keep this principle in mind when designing web maps in a multi-scale environment since not all layers should necessarily be visible at all scales. This blog entry shows you how you can use the visibility range settings in ArcGIS.com Map Viewer so that operational overlays are only visible at certain scales. By taking a thoughtful approach to designing the content for your layers and setting their visibility range you can optimize the viewing experience for your map reader rather than bombard them with a mashup of tangled symbols. Continue reading
By Kenneth Field, Esri Research Cartographer
Mapping Center Team member Kenneth Field recently received another award for his map ‘The Beautiful Game: A World of Football’. In addition to awards for the map at the 2010 Esri UC, Ken was presented with the John C. Bartholomew award for small-scale mapping at the recent British Cartographic Society Symposium in the UK. The coveted award is presented for originality and excellence in thematic (non-topographic, 1:100,000 and smaller) cartography. The award is made by Collins Maps, publishers of Collins and Times world atlases, and the family of the late John C. Bartholomew.
By Dr. A Jon Kimerling, Professor Emeritus, Oregon State University
If you’ve used any raster DEM data to make maps you may have at one time or another asked yourself, “What is the appropriate map scale for the DEM I am using to make the map?” This question is tied closely to a basic principle of map compilation that you may have learned in your beginning cartography course: “Always compile your map from source materials of the same or larger map scales”. In our age of digital elevation models and other raster datasets, this basic principle of map compilation can be restated as: “Always create your raster map from data at the same or higher spatial resolution than the ground resolution of your map display grid cells”. The ground resolution of your map display grid cells will depend on the scale of your map. An equation you can use that relates map scale expressed as a representative fraction (1/x), DEM cell resolution, and map display resolution is:
Three new templates have been posted to our Roads & Highways Resource Center and are available in the Gallery! Check out these analysis tools and web viewers.
The Crash Safety Analysis Template provides three industry standard tools – sliding scale, spot, and strip. These tools are now available in ArcGIS 10 as geoprocessing tools. The crash safety analysis tools can also be accessed through the web by using the Crash Safety Web Analysis Template. In this template the same geoprocessing tools are published with ArcGIS Server and consumed in this configurable Flex widget.
Our Crash Safety Dashboard Template has also been updated to the Flex 2.1 framework. This new framework allows for increased functionality as well as a more user friendly sample viewer layout.
By Rajinder Nagi, Esri Cartographic Product Engineer
I am sure if you have used any imagery data to make maps then you have at one time or another asked yourself, “What resolution should the image be for me to be able to detect features in it?” Well, you don’t need to guess, because there is a mathematical relationship between the map scale and the image resolution.
In 1987, Waldo Tobler, renowned analytical cartographer (now emeritus from University of California-Santa Barbara) wrote, “The rule is: divide the denominator of the map scale by 1,000 to get the detectable size in meters. The resolution is one half of this amount.” Tobler goes on to note, “Of course the cartographer fudges. He makes things which are too small to detect much larger on the map because of their importance. But this cannot be done for everything so that most features less than resolution size get left off the map. This is why the spatial resolution is so critical.”