This article demonstrates the use of commercially available Synthetic Aperture Radar (SAR) imagery from satellites as a tool to augment electro-optical (EO) multispectral and panchromatic satellite imagery typically used for analysis. While concealed to visible imaging satellites, recent SAR imagery revealed the presence of the North Korean SINPO-class experimental ballistic missile submarine (SSBA) and its submersible test stand barge positioned beneath a recently constructed, dockside awning designed to conceal and environmentally protect these vessels.
More: https://www.38north.org/2020/01/sinpo010320/