Here is more from the New York Times:
North Korea is moving ahead with its ballistic missile program at 16 hidden bases that have been identified in new commercial satellite images, a network long known to American intelligence agencies but left undiscussed as President Trump claims to have neutralized the North’s nuclear threat.
The satellite images suggest that the North has been engaged in a great deception: It has offered to dismantle a major launching site — a step it began, then halted — while continuing to make improvements at more than a dozen others that would bolster launches of conventional and nuclear warheads.
The existence of the ballistic missile bases, which North Korea has never acknowledged, contradicts Mr. Trump’s assertion that his landmark diplomacy is leading to the elimination of a nuclear and missile program that the North had warned could devastate the United States.
The secret ballistic missile bases were identified in a detailed study published Monday by the Beyond Parallel program at the Center for Strategic and International Studies, a major think tank in Washington.
The program, which focuses on the prospects of North-South integration, is led by Victor Cha, a prominent North Korea expert whom the Trump administration considered appointing as the ambassador to South Korea last year. His name was pulled back when he objected to the White House strategy for dealing with Kim Jong-un, the North Korean leader.
The report, which was also written with Lisa Collins, a research fellow at the center, supplemented the satellite imagery with interviews of North Korean defectors and government officials around the world.
More about the report can be found here and here. Besides Victor Cha and Lisa Collins, the report was also co-authored by Joseph Burmudez, who is concurrently a senior fellow at CSIS, senior adviser and imagery analysts for the Committee for Human Rights in North Korea (HRNK), author for IHS Markit, and publisher/editor of KPA Journal.
CSIS also uses satellite intelligence in many of its reports on China.
Here is a previous Think Tank Watch piece about the satellite imagery that CSIS uses, as well as funding for the project.