Conspiracy theorists come back, all is forgiven......
I thought I'd just check again the US counterpart to Burghfield, which is the Pantex facility outside Amarillo, to see if they also had these Faraday Cages;
35°18'29.99"N 101°33'28.85"W
....and since I last looked someone has left the shutter open for too long, and now we have a highly over-exposed picture which shows no detail. Three months ago it was a far superior image with balanced exposure.
But then again I guess Google Earth is probably the only recon system that the North Koreans have at present...