Do you know for sure?
I'd rather not have to take a gamble on my enemy's Resource Scan saying they only have 2k gold and 2k wood when in reality, they have something like 8k of each.
EDIT: Actually, the wiki cleared it up for me. There was a line in there that said something like, "Advanced military scan is only ~25% accurate, which means it is much less accurate than the Military scan."
So, yeah, the lower the percentage, the less accurate it is.
I really hope this guy doesn't just spring up an army on me.