Those camps have been statically in place for decades - so I always assumed that the Norks had a grid coordinate for every barracks, every parked tank, etc...and a rocket pointed at each one.
I also believed that the Norks had to know the best time to attack was Saturday night, since so many guys went to town to get drunk.
Im sure the NKs do know. Since they have plenty of spies, some of them very cute and cuddly.