Interesting that the company are quoting an operating height (50m or so) when the picture shows it way higher. Why oh why are they white, cunningly disguised as a cloud when they should be ORANGE.
As for anemometer masts, they are major hazard to low flying and IMO should be notamed. I am pretty sure that they require planning permission, so their locations should be available from the local council. Yet more paperwork to plough through before going flying!