They also put to pragmatic social and geopolitical use a lot of tech in a low-budget way: imaging from Planet Labs, machine learning in inage analysis, etc. And they go through how they pit them to use in detail.
According to the latest podcast, which goes into this topic in detail, they don't use machine learning at all (but would like to try it): https://www.armscontrolwonk.com/archive/1205801/south-korean...
Instead, they're finding missile sites by manually tracking information leaks in various places. E.g. that podcast discusses how they found a secret South Korean site partially from publicly available images (it had a really distinctive design), and from things like browsing the LinkedIn profiles of people known to work there, which would mention that they worked in some nearby town or county.
https://www.armscontrolwonk.com/