|1804||Lewis and Clark began to map and gather intelligence and other information on territory from St. Louis, Missouri, to the Pacific Ocean|
|1813||The Topographical Engineers began conducting surveys to facilitate the safe movement of troops for the War of 1812|
|1835||The Navy began to produce nautical charts and, 3 years later, to make astronomical observations|
|1889||The Army began to collect and compile information on geography and foreign forces, and to communicate it to military attachés during the Spanish-American War|
|1911||First photoreconnaissance flight. Aerial photography became a major contributor to battlefield intelligence during World War I|
|1922||First modern bathymetric chart, made using sounding data collected from a Navy ship|
|1928||The Army Air Corps began producing aeronautical charts|
|1941||Second World War aviation enabled photogrammetry, photo interpretation, and geodesy to replace field surveys|
|1953||Navy aircraft began measuring magnetic variations around the Earth; project U.S. Magnet continued until 1994|
|1956||High-altitude U-2 aircraft began to carry out manned reconnaissance missions, becoming the primary source for intelligence gathering over the Soviet Union and other denied areas|
|1960||Successful return of imagery from Corona, the first photoreconnaissance satellite system in the world|
|1960||World Geodetic System (WGS 60) defined an Earth-centered orientation system and formed the basis of current global positioning systems|
|1966||Launch of the Geodetic Earth Orbiting Satellite, the first dedicated satellite for geodetic studies|
|1974||First electronic dissemination of near-real-time, near-original-quality overhead imagery to support rapid targeting and assessment of strategic threats|
|1978||Launch of the first four Global Positioning System satellites, which enabled accurate measurements of position, velocity, and time|
|1994||Presidential directive PDD-23 directed the National Imagery and Mapping Agency to acquire commercial satellite data|
|1995||Unmanned aerial vehicles began taking streaming video during reconnaissance flights|
|2000||The Shuttle Radar Topography Mission began to acquire elevation data over about 80 percent of the Earth’s surface using interferometric synthetic aperture radar|
|2005||Surface warships began to navigate using digital nautical charts|
|2006||First automatic construction of the three-dimensional world from diverse sources of photographs and images|
SOURCES: Day et al. (1998); Snavley et al. (2006); Clarke (2013a); NGA historical reference chronology, <https://wwwl.nga.miV About/OurHistory/Pagesl default.aspx>.
analysis and the evaluation of natural phenomena and human activities at the Earth’s surface. NGA’s current model for producing geospatial intelligence is illustrated in Figure 1.1 and an example of an information product is shown in Figure 1.2.
Through most of the 20th century, responsibility for specific aspects of mapping, charting, aerial photography, and eventually satellite reconnaissance was distributed among multiple defense and intelligence agencies and departments. In 1996, mapping, imagery acquisition and analysis, and intelligence production were brought together from the Defense Mapping Agency, the Central Imagery Office, and other imagery and mapping departments in a single agency—the National Imagery and Mapping Agency (NIMA).1 NIMA’s primary focus was on acquiring and providing imagery and maps to intelligence agencies. Increasing demands for speed, accuracy, and synthesis of geospatial information—especially since the September 2001 terrorist attacks in the United States—led to the concept of geospatial intelligence or GEOINT, the use of imagery and geospatial data to describe and depict features and activities and their location on the Earth. In 2003, the agency’s name was changed to the National Geospatial-Intelligence Agency to emphasize its mission of producing geospatial intelligence.
NGA is part of the Department of Defense, and it is one of 16 federal agencies responsible for national intelligence. Its emphasis is on military and intelligence
1 See NGA historical reference chronology, <https://www1.nga.mil/About/OurHistory/Pages/default.aspx>.