After North Korea's epic failure of a rocket launch last month, it's hard to get too concerned about the report that it appears to be upgrading its launchpad to handle even bigger rockets than the Unha. It's still interesting news, but the most interesting thing about the Associated Press report from Matthew Pennington is the source of the original research on which it is based.
The news comes from a series of photos and analysis from the U.S.-Korea Institute at Johns Hopkins School of Advanced International Studies. If you don't require soundbites from SAIS higher-ups, it's more fun and informative to skip the AP and just scan the report on the institute's website, 38 North. It has all their satellite photos (which don't appear on the AP's story), plus descriptions of what you're seeing. It's a little jargony, but provides a lot more detail than the AP about what you're actually seeing:
Three developments strongly suggest that this new pad is designed to launch rockets larger than the recently tested Unha, either more capable, liquid fueled space launch vehicles or missiles with intercontinental ranges. (Figure 2 is an enlargement of the main area of the new facility.) First, the flame trench—the dark object in the center—is larger than those at the original Musudan-ri launch pad and the new Tongchang-ri. The new trench measures 33 meters in length, 9.5 meters wide, and 6 to 8 meters deep. The circular ring—with an outside diameter of 14.5 meters and an inside diameter the same as the tranche’s width of 9.5 meters—marks the beginning of the pad. (A crane can be seen outside the ring). A white object inside the ring is probably the end wall of the trench.
What the AP provides is context, including the detail that "the top U.S. envoy on North Korea, Glyn Davies, who is meeting this week with counterparts from Japan, South Korea and China, warned Monday that the North conducting an atomic test would unify the world in seeking swift, tough punishment."
But that kind of talk is always in the air when diplomats get stern about North Korea. What this exercise is about is examining satellite photos and getting a look behind the often monotone news reports at what actual intelligence types see and think about when they look at spy photos.