With the latest update to ArcGIS Online you can now tone down your basemap to make other layers “pop” by using transparency. We covered a different technique to accomplish this in an earlier post and also covered some new basemaps in progress in another post on the Esri Insider. But let’s take a closer look at how the new basemap transparency can be used to tone down your basemap.
Here’s our map showing faults in the south-central portion of Nevada. The purple fault lines are little hard to see against the dark imagery background, and since these are from a published service we can’t interactively change the color.
We could choose a different basemap, but another alternative if we want to use the same imagery basemap is to adjust its transparency.
Hover over the basemap in the map contents and click the arrow that appears to choose transparency and display the transparency slider:
Here’s our improved map that enables the purple fault lines to be more easily seen.
By Aileen Buckley, Mapping Center Lead
The Ocean Basemap (Ocean_Basemap) map service was published recently on ArcGIS Online (services.arcgisonline.com, server.arcgisonline.com). This global map shows the sea floor of the oceans, along with both surface feature names and subsurface feature names. The Ocean Basemap is designed for use by GIS professionals interested in bathymetry, marine science and conservation, and ocean mapping.
We’re working on some new basemap styles and capabilities that will offer additional basemap choices to create a better backdrop for certain kinds of information. The one shown below was used in our recent Super Bowl Edition FanMap:
Note that the basemap is a dark slate gray, with muted colors used throughout that allows the symbols to show more clearly, and also doesn’t compete with the primary information subject of the map – fan votes for Superbowl favorites.
Recently someone asked me how to tone down the World Imagery basemap to make their symbols “pop” and wondered if there was a way to darken things a bit. That ended up being a great enhancement request, and we’ll be adding some additional options for you to control the brightness (and potentially more) in a future update. But here’s a little trick that you can use now.
Below is our basemap with several symbols used to show the route for a cross-town cycling event. We’re using the World Imagery basemap, and the symbols just don’t seem to “pop” as much as we’d like.
The imagery basemap is very bright and competes visually with our cycling route details. We toned down the basemap, and made it darker (as shown below) to make the symbols “pop.”
We’ve exaggerated the darkness a bit to make our point, but you get the idea. The symbols are definitely more visible with the darkened imagery basemap.
Ok, so how did we do it? It’s simple and there are two approaches you can take. One is to publish an ArcGIS layer service that’s a large, shaded polygon and add that to your map, adjusting the transparency for the desired effect. Another technique is to add a polygon map note, and adjust the transparency of the note feature. Both provide the desired result, and are simple enough to do.
Below is a webmap embedded in a public website that uses the same technique to make the symbols “pop.” This map uses a ArcGIS layer service that’s a partially transparent, off-white polygon.
By Aileen Buckley, Mapping Center Lead
I recently printed a wall map from the World Topographic Community Basemap, and I thought some of you might also like to do that to showcase your geographic location, especially if your agency contributed data to the map. The wall map can be created in ArcMap and exported to a number of formats that you can print from. Here are the steps to produce these large-format wall map layouts in ArcMap:
By Mamata Akella, Esri Design Cartographer
Over the past several months, there have been many updates to the World Topographic Basemap which is part of Esri’s larger Community Basemap initiative. If you are interested in tracking the most recent additions and/or the latest news about the map and the program, there are a couple of websites that you can visit.
When editing, you can incorporate basemap layers into your map to increase productivity. If you have a complicated map, such as a water utility network containing many detailed features and underlying background layers, you can spend a lot of time waiting for the map to refresh whenever you pan or zoom. With ArcGIS 10, you can minimize this by creating a basemap layer containing the contextual reference layers that you are not editing, such as imagery or streets.
A basemap layer is a special type of group layer that is drawn using optimized map display logic that utilizes a local cache to refresh the map quickly. Basemap layers also help reduce network traffic since ArcMap does not need to contact the server repeatedly to retrieve the map extent. To create a basemap layer, right-click the data frame name in the table of contents, click New Basemap Layer, and drag the layers into it. Although a basemap layer can contain any layer format, such as feature classes, shapefiles, Web services, or rasters, some content types are more appropriate for use in basemaps. This post shows you how to identify layers suitable for basemaps, use the editing environment with basemaps, and improve your basemap performance.
Choosing the layers to be in a basemap layer
To use basemap layers effectively, they should truly form a basemap beneath the layers that you are editing. If you edit data for a water district, your operational layers, such as manholes, water main lines, and valves, cannot be part of a basemap layer because you need to edit them and have the features be drawn dynamically to access the latest updates from their data sources. However, any supporting reference layers that you normally display underneath the utility data can be placed in a basemap layer for enhanced performance. For example, you could include a land base of parcel boundaries, buildings, streets, and other built features, as well as imagery layers, in one or more basemap layers. The layers in the basemap look the same as they did before; they just draw faster now. Here is an example table of contents showing the kinds of underlying layers that could be basemap layers.
Basemaps tend to be relatively static and typically are updated on an infrequent basis. Rasters and service layers are good candidates for basemap layers because they are stable and can benefit greatly from improved drawing speed. ArcGIS Online, for example, provides imagery, topography, streets, and other content from several different sources that you can use in your maps. If you click the arrow next to the Add Data button and click Add Basemap, you can add layers from ArcGIS Online directly into a new basemap layer.
Editing when basemap layers are in the map
Because basemap layers are cached, there are limitations on what you can do with them. For example, you cannot edit the layers in a basemap or change the layer symbology. If you need to make edits or layer updates, drag the layer out of your basemap, make the changes, and drag the updated layer back into the basemap layer.
If you attempt to start an edit session with an editable layer in the basemap, ArcMap shows you a warning message. You can edit all the other layers in that workspace, but you cannot edit the layers in the basemap even if they belong to the same geodatabase. If the basemap contains any layers that are related to other editable layers through relationship classes, topologies, geometric networks, or parcel fabrics, or shares data sources with layers outside the basemap, you cannot start editing at all until you move the layer out of the basemap. You can double-click an entry in the Start Editing dialog box to open an ArcGIS Desktop Help topic containing more information on how to fix these and other issues that occur when you start editing.
Although you cannot edit the layers inside a basemap, you can snap to feature layers in a basemap layer. For example, if you were creating a new waterline in relation to building locations, you can still snap to the Building Footprints layer even though it is inside the basemap.
Improving basemap layer display and performance
With basemap layers, you can pan continuously and smoothly by pressing the Q key or holding down the mouse wheel. The rest of the map layers are redrawn once you release the key or the wheel button. If you find that the layers on top of the basemap are difficult to see, you can dim the display of the basemap using the Effects toolbar. This makes the basemap appear washed out and partially transparent, helping your operational layers stand out more. This can be useful for editing, especially in cases where your basemap layers contain orthographic images or other richly colored content that may obscure the details of layers on top of them.
Once you create a basemap layer, you can run diagnostic tests to check its performance. You can do this by right-clicking the basemap layer and clicking Analyze Basemap Layer to display a window listing ways you can speed it up even further. You might see messages indicating that the layer is being projected on the fly or uses complex symbology, which can slow down drawing. For example, the message “Layer draws at all scale ranges” is a suggestion to set a visible scale range on the layer since there is no need to display the layer when the features are too detailed or too coarse at certain map scales. You can right-click an entry to open the Layer Properties dialog box, where you can resolve many of the issues to get the most out of basemap layers.
Data used in the examples is modified from the Water Network Utilities Template by Esri and Fort Pierce, Florida.
The following links give you the recommended set of ArcGIS Online basemaps for the version of ArcGIS Desktop you are using:
Notes for 9.2 users: The ArcMap link above takes you to a set of MXD files you can open in ArcMap 9.2 by simply clicking ‘Open’ if you have at least 9.2 Service Pack 5 installed. If you are using 9.2 SP4 or earlier, then right-click the ‘Open’ button and choose your web browser’s option to save the MXD file locally, then open it manually from the location you save it to. The ArcGlobe link above takes you to a set of globe services. To add one of these services into ArcGlobe 9.2, click the title of the entry to go to its full description page, then look in the description for the ArcGIS Desktop File(s) section, where you’ll see an entry for a LYR file (and in some cases a 3DD file). Right-click the entry for the LYR file and choose your web browser’s option to save the file locally, then add it manually into ArcGlobe from the location you save it to using ArcGlobe’s Add Data dialog.
Tip: You can access the basemaps directly from inside the applications too starting at 9.3. These queries above return the same set of basemaps that you can access using the following commands:
ArcMap/ArcGlobe 9.3 File > Add Data From Resource Center
ArcMap/ArcGlobe 9.3.1 File > Add Data From ArcGIS Online
ArcMap 10.0 File > Add Data > Add Basemap
ArcGlobe 10.0 File > Add Data > Add Data From ArcGIS Online
By Charlie Frye, Esri Chief Cartographer
What role do you expect a base map to play in your GIS?
Some say, “The base map is the part of the map I don’t have to make.” To that, I say, who should make it, who will use it, and what will they do with it?
Today a wide variety and diversity of base maps are proliferating with emerging Internet technologies such as mash-ups on Google Earth, ArcWeb Services, your own ArcGIS Server maps, etc. Our intent is to consider, or depending on your perspective reconsider, the functionalities that a base map, particularly a GIS base map should have. Are all these new base maps what you need? Continue reading