Photography, High-Altitude

Photography, High-Altitude

The United States conducts, and has conducted, operations in high-altitude photography for a number of purposes. In addition to intelligence-gathering operations such as that of the CORONA program in the 1960s, civilian undertakings such as those of the U.S. Geological Survey (USGS) have an obvious, if unspoken, intelligence application. High-altitude photography, which offers several advantages over ground-based surveillance, has evolved over the years, along with the equipment: from balloons to prop planes, jets, and satellites.

High-Altitude Photography and its Applications

High-altitude photography enables the coverage of large areas—for example, a military installation—in a single photographic frame. For a larger region such as a metropolitan area or state, it may be necessary to form a mosaic of several photographs. The more sophisticated the photographic equipment, the more the area that can be portrayed with a reliable degree of photographic resolution.

The same goes for the technology necessary to keep the camera aloft: a satellite, because it orbits at a considerably greater height than the highest-flying plane, by definition possesses a much better vantage point for breadth of coverage. The July 1976 issue of National Geographic, which commemorated the U.S. bicentennial, illustrated this breadth dramatically with a fold-out aerial photograph of the United States patched together from hundreds of satellite photographs.

From balloons to satellites. In the mid-nineteenth century, European and later American armies began using balloons as observation platforms. From this it was a logical step to mount camera equipment on the balloons. The advent of the airplane as an instrument of both combat and surveillance was all but concurrent with the use of photographic equipment for intelligence purposes. By the end of World War I, the use of high-altitude craft for the gathering of photographic intelligence was firmly established.

The use of airplanes in surveillance did not rule out the application of balloons. These included both ordinary balloons, which had made their debut in the late eighteenth century, as well as airships, or guided balloons, pioneered in the last third of the nineteenth century. As late as 1956, the U.S. Air Force was using balloons in Project GENETRIX, a failed effort to conduct surveillance of Eastern Europe, the Soviet Union, and the People's Republic of China.

Yet the age of the jet and the satellite was well under way by then. Already the Central Intelligence Agency (CIA) was putting the finishing touches on its plans to employ the high-speed U-2 aircraft for overflights of the Soviet Union and other countries, and in 1957, the Soviets themselves launched the first artificial satellite, Sputnik.

Satellites. In the years since, the United States has used satellites in a number of information-gathering capacities. Significant among these operations was CORONA, which involved the launch of some 145 satellite flights between 1960 and 1972. CORONA collected some 800,000 images, most of which covered an area about 10 miles (16 km) wide and 120 miles (193 km) long. Resolution was accurate for objects as small as 6.6 feet (2 m).

CORONA operations took place before the era of digital imaging, and therefore images had to be sent back to Earth manually, by means of film capsules attached to parachutes and retrieved by an Air Force C-119. Information gathered by the CORONA systems, which were designated KH-1, KH-2, KH-3, KH-4A, and KH-4B by the intelligence community, was declassified by Executive Order 12958 in 1995. Today USGS controls most of the images.

USGS photographic operations. A unit of the Department of the Interior, USGS is responsible for measuring and mapping areas of Earth's surface, particularly those in the United States; for managing resources; and for minimizing threats to life and property by identifying hazards. Although USGS is ostensibly outside the security and intelligence component of the federal government, its application in those areas is clear. Among its undertakings is the Military Geology Project, which is primarily concerned with monitoring nuclear tests, and breaches of nuclear treaties, worldwide.

Geologists make extensive use of remote sensing, or the gathering of data without actual contact with the materials or objects being studied. High-altitude photography is among the most significant techniques of remote sensing, and USGS has used airplanes and satellites for a number of projects.

Among these was the National High Altitude Photography Program (NHAP), launched in 1980 to collect aerial photographic images of the 48 conterminous states every five to seven years. Undertaken in an effort to eliminate duplication of government mapping programs, NHAP in 1987 became the National Aerial Photography Program (NAPP). NHAP acquired photographs at 40,000 feet (12,190m), and NAPP at half that altitude. Both used a 6-inch focal length lens, which for NHAP obtained black-and-white pictures and for NAPP either color infrared or black-and-white. NHAP also used an 8.25-inch lens to obtain color infrared images.

At a much higher altitude, USGS has also been one of the principal agencies involved in the Landsat satellite program, which began with the launch of Landsat 1 in 1972 and continued in the early twenty-first century with Landsats 5 and 7. Tasked primarily with providing information on environmental hazards and natural disasters, Landsat 7 orbits the planet every 99 minutes. Its photographic equipment, while noted for its high spatial resolution—98 feet (30 m)—in comparison to that of other scientific satellites, is of relatively low resolution compared to that of intelligence satellites such as CORONA three decades earlier.

Overflights. Even with satellites in space, the United States has continued to employ overflights, or missions by spy planes over enemy countries to collect intelligence via electronic or photographic equipment. The concept of the overflight, which involves the gathering of information on strategic activities in the country rather than the tactical activities of its enemy forces, dates back at least to 1952, when the United States sent B-47 Stratojets over Soviet airspace.

Perhaps the most well known use of overflights was that of the U-2 over the Soviet Union, a fact that came to world attention when pilot Francis Gary Powers was shot down in 1960. Though it made its debut in 1955, the U-2 was still being used in 2003, as part of United Nations weapons inspector's work in Iraq. Even in the early 1960s, the photographic equipment aboard the U-2 was exceptional: its camera had a 944.7-millimeter lens, and was capable of capturing an area measuring some 125 miles (201 km) by 2,174 miles (3,499 km) in 4,000 photographs.

The SR-71 Blackbird made its debut in 1964, when it was presented as a successor to the U-2. In fact the two flew concurrently, and the U-2 remained in the skies during a period from 1990 to 1995, when the SR-71 was mothballed due to its high costs of operation. Much faster and higher-flying than the U-2, the SR-71 has been used to photograph operations in enemy countries ranging from China and North Vietnam to Libya and Iraq to Cuba and the communist Nicaragua of the 1980s. An SR-71 photographed China's first hydrogen bomb explosion in 1967.



Barrett, E. C., and L. F. Curtis. Introduction to Environmental Remote Sensing. New York: Chapman & Hall, 1992.

Walker, James W., and Steven Leroy De Vore. Low Altitude Large-Scale Reconnaissance: A Method of Obtaining High Resolution Vertical Photographs for Small Areas. Denver, CO: Interagency Archeological Services, National Park Service, 1995.


Declassified Intelligence Satellite Photographs. < > (February 13, 2003).

United States Geological Survey. < > (February 13, 2003).


Balloon Reconnaissance, History
NIMA (National Imagery and Mapping Agency)
Photographic Interpretation Center (NPIC), United States National
Satellites, Non-Governmental High Resolution
Satellites, Spy

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