Base Map Layer

Introduced in Esri ArcGIS Desktop 10, Basemap layers provide map layer functionality designed to enhance rendering performance. Basemap layers draw continuously during navigation to help eliminate white space when panning and editing. The substantial performance increase is enabled by a fast drawing engine and back-end caching.

Basemaps support common layers, renderers, and data source types. More than one basemap layer can be used in a map, but performance varies depending on the availability of hardware resources such as RAM.

Basemap layers are designed to contain pre-authored content, such as rasters or imagery. As a trade-off for enhanced drawing and rendering performance, most geoprocessing tools cannot be used on basemap layers. For example, basemap layer symbology cannot be changed; however, key tools such as Identify and Snap function normally.

In ArcGIS Desktop 10, the Table of Contents displays warning flags where unsupported content, display, and performance issues exist. The Analyze Basemap Layer tool helps to identify errors and issues with basemap (and other) layers.

Basemap layers are a Desktop enhancement and do not deliver performance enhancements in ArcGIS Server. If a basemap layer is in a MXD file, use optimized map services to draw dynamic or cache content for the best web performance.

Basemap layers can also utilize the Maplex labeling extension.

Time events in basemap layers are not currently supported by Esri.