Base Layers

Base Layers

Base Layers are mutually exclusive layers, meaning only one can be enabled at any given time. The currently active base layer determines the available projection (coordinate system) and zoom levels available on the map.
Whether a layer is a base layer or not is determined by the isBaseLayer property on the layer. Most raster layers have the isBaseLayer property set to true by default. It can be changed in the layer options.
Base Layers always display below overlay layers.