South Korea is bright, North Korea is dark. This amazing image is included in the standard US Department of Defense briefings on North Korea. It was mentioned in a news briefing on 23 December 2002 by Defense Secretary Rumsfeld, who stated that "If you look at a picture from the sky of the Korean Peninsula at night, South Korea is filled with lights and energy and vitality and a booming economy; North Korea is dark." There are a number of versions of this image in circulation, with visible differences that vary according to the conditions at the time the imagery was acquired.
The image was made by the orbiting Defense Meteorological Satellite Program (DMSP) satellite over regions of the world at night. The DMSP is a Department of Defense (DoD) program run by the Air Force Space and Missile Systems Center (SMC). The Defense Meteorological Satellite Program satellites carry the Operational Linescan System (OLS) in low-altitude polar orbits. These satellites record nighttime data. The Operational Linescan System has a unique low-light imaging capability developed for the detection of clouds using moonlight. In addition to moonlit clouds, the OLS also detects lights from human settlements,fires, gas flares, heavily lit fishing boats, lightning and the aurora. It is possible to distinguish four primary types of lights present at the earth's surface: human settlements, fires, gas flares, and fishing boats.
http://www.globalsecurity.org/military/world/dprk/dprk-dark.htm
