viewBoundScale

The scale factor to apply to the bounding box parameters when retrieving the network link. Only applied if KmlViewRefreshMode is a value other than KmlViewRefreshMode.Never. A value of 1.0 covers the visible extent. Values less than 1.0 specifies to use less than visible extent, while values greater than 1.0 specifies to use beyond visible extent. The default value is 1.0. Refer to the KML Link documentation for more details.