In this case, my client was in the process of planning a direct microwave radio link between Wrotham (Kent) and Royal Tunbridge wells, all of the web based topological data indicated that line of sight could be achieved, however topological data does not take tree heights into account.
I was engaged to perform a basic tree height survey on the intervening high spot in Sevenoaks.
This was a lot more cost effective than employing a cherry picker for this purpose, the ground was also waterlogged at the the time so it would have been highly unlikely that the high platform truck would have been able to enter the field without getting stuck.
Red Cross indicates the centre of the camera to the ground.