Rather closer to Chilbolton airfield than Popham, but also in the training area routinely used by Thruxton, and the area used by Middle Wallop for Apache training.
I'm sure if I tried hard I could think of a more stupid place to put a DZ, but I'd have to try hard.
If they want a DZ in that area, the place to put it would be adjacent to, or within, SPTA or Porton range.
G