When you build a map cache, you can choose to match the tile dimensions and scales used by ArcGIS Online, Google Maps, or Bing Maps. Matching the tile dimensions and scales of these online map services leads to fast-performing overlays in client applications. If you plan to overlay your map service with ArcGIS Online, Google Maps, or Bing Maps, follow this workflow when you create your map:
Author the map
You'll originally create the map in ArcMap by adding data and symbolizing it appropriately. When designing your map, use the WGS 1984 Web Mercator (auxiliary sphere) coordinate system, which is the same coordinate system used by ArcGIS Online, Google Maps, and Bing Maps.
Change the coordinate system to WGS 1984 Web Mercator (auxiliary sphere)
To change the coordinate system, follow these steps:
- Right-click the data frame name (the default is Layers) in the ArcMap table of contents and choose Properties.
- Click the Coordinate System tab.
- Click Projected Coordinate Systems > World > WGS 1984 Web Mercator (auxiliary sphere).
- Click OK.
If you do not change the coordinate system at the time you are designing your map, it is automatically changed at the time you attempt to create a map cache using the ArcGIS Online/Bing Maps/Google Maps tiling scheme.
Earlier versions of ArcGIS recommended using the WGS 1984 Web Mercator projected coordinate system. The WGS 1984 Web Mercator (auxiliary sphere) coordinate system is an equivalent coordinate system that simplifies the datum transformations required for some datasets.
Design at the same scales used by ArcGIS Online, Google Maps, and Bing Maps
Users of your map service will want to see it at the scales used by ArcGIS Online, Google Maps, and Bing Maps. In this case, you should only design your map at those scales. But how do you know what those scales are?
You can load the scales into the ArcMap drop-down list of scales by doing the following:
- Open your map document in ArcMap.
- On the Standard toolbar, click the drop-down list of scales and choose Customize This List.
- Click Load and choose ArcGIS Online/Bing Maps/Google Maps.
- Click OK to apply your changes. You can now see the set of scales used by these popular web mapping services and easily jump between them using the drop-down list.
You only need to design your map to look good at the scales at which it will be cached. If you do not plan on caching your map at the larger scales, you do not need to do any design work at those scales.
Set scale ranges on your layers so that just the right amount of data and number of labels are visible at each scale, symbolized appropriately. When setting your scale ranges, avoid toggling layers on and off at or near the scales at which you are designing.
You may need to make copies of your layers so that you can symbolize them differently at various scales. The ArcMap table of contents can contain multiple copies of a layer, each with its own symbology and scale ranges. To copy a layer, right-click it in the ArcMap table of contents and click Copy. Then right-click the data frame name and click Paste Layer(s).
Define the map cache tiling scheme and publish the map as a service
After you've finished authoring your map document in ArcMap, you'll need to publish it as a map service to your ArcGIS Server site. During this process, you will set up properties for your service in a dialog box called the Service Editor. This contains a Caching tab where you can set properties for your map cache.
When setting cache properties, you should choose the ArcGIS Online/Bing Maps/Google Maps tiling scheme. There are many other cache settings you can adjust.
You can choose to build the cache automatically at the time the service is published or build it later on your own. You do not have to build cache at all the scales in the tiling scheme, especially if it would take an unmanageable number of tiles to cover your map at the largest scales. However, you should not delete the scales themselves from the tiling scheme.
See Creating a map cache to get started with caching.