toGeoJSON does not by default produce bbox properties because they can be derived from existing GeoJSON data, but in this case a GroundOverlay does very literally suggest a box, and it doesn't hurt to represent that box literally in the output.
This only applies to GroundOverlays with aligned rectangles specified by LatLonBox, and not those specified by <gx:LatLonQuad>, which can contain rotated boxes. Also, the bbox generated is literal - if a rotation is also provided, it is not incorporated into the bbox.
toGeoJSON does not by default produce
bboxproperties because they can be derived from existing GeoJSON data, but in this case a GroundOverlay does very literally suggest a box, and it doesn't hurt to represent that box literally in the output.This only applies to GroundOverlays with aligned rectangles specified by LatLonBox, and not those specified by
<gx:LatLonQuad>, which can contain rotated boxes. Also, the bbox generated is literal - if arotationis also provided, it is not incorporated into thebbox.