My RadPolarChart represents an antenna radiation pattern. I need to draw an annotation relative to the origin. How can I do this? My radial axis is NumericRadialAxis but I cannot seem to figure out the origin value, and PolarCustomAnnotation wants polar and radial coordinates.
The attached image represents an antenna mounting image. i want to center the small ellipse around the origin. I'm using a DrawingImage in XAML to define the geometry.