Handbook of intelligence studies / edited by

JEFFREY T. RICHELSON
means for obtaining an overhead vantage point. According to Chinese and Japanese folklore,
spotters ascended in baskets suspended from giant kites or were strapped directly onto to them.
In April 1794, French forces were reported to have kept a balloon aloft for nine hours, with its
passenger, Colonel Jean-Marie Joseph Coutelle, making continuous observations during the
battle at Fleurus, Belgium. Balloons were used to carry observers and, less frequently, cameras,
during the American Civil War. 2
As a result of the Wright Brothers’ invention of the airplane in 1903, a key intelligence
resource in World War I were reconnaissance aircraft – planes equipped with cameras that could
photograph enemy fortifications, troop deployments, and the battlefield. During, and in the
years leading up to, World War II photographic reconnaissance aircraft played an even greater
role. Britain managed to conduct covert flights over Germany, while German aircraft brought
back photographs of Soviet territory prior to the German invasion of the Soviet Union in
June 1941. During the war, British and American planes photographed German military
and industrial installations and areas on a regular basis – to aid in targeting and damage
assessment. 3
The advent of the Cold War ensured that overhead reconnaissance retained its importance,
particularly for the United States, as it sought to pierce the veil of secrecy established about
almost every aspect of Soviet life – especially its military capabilities. The possibility that a
satellite could be outfitted with a camera to take pictures of any place on earth that it passed
over was noted by the RAND Corporation as early as 1946. In August 1960 that vision was
realized when the United States orbited a camera-carrying satellite codenamed Corona.
A satellite such as Corona, in a polar orbit that took it over all of the earth from pole to pole,
could photograph Soviet military activities in the northern reaches of the Soviet Union, airfields
in the Middle East, and battles in sub-Saharan Africa. In the decades since the first Corona
orbited the earth, the capabilities of such satellites have increased dramatically – as has the
number of nations that operate such satellites.
The photographic reconnaissance satellite has become the imagery satellite – for capturing
the visible light reflected by an object is not the sole means of obtaining an image of a target.
The infrared radiation (heat) reflected by an object can also be used to produce an image during
daylight, and in the absence of cloud cover (which blocks the reflected radiation). The heat
independently generated by an object can also be used to form an image, even in darkness.
That second type of infrared imagery can provide data on developments taking place at night
that ordinary visible light sensors cannot.
A third means of obtaining imagery from a satellite is through the use of radar (radio
detection and ranging). Radar imagery is produced by bouncing radio waves off an area or an
object and using the reflected returns to produce an image of the target. Since radio waves are
not blocked by clouds, radar imagery can be obtained not only day or night but even when
clouds block the view of a satellite’s visible-light and infrared imagery sensors.
Imagery satellite capabilities have also advanced in a number of other ways. The most
important is the development of real-time capabilities. The Corona satellites and several other
US and Soviet spy satellite systems operated in the 1960s, 70s, 80s were “film-return” satellites.
An image was formed on film, just as an image would be formed on a conventional camera.
When the film supply carried by the satellite was exhausted, part of the satellite (in the case of
the United States, a capsule) carrying the film would be returned to earth and recovered.
Today, almost all imagery satellites are digital and operate in near real-time – the optical
systems rely on charged couple devices which translate the varying visible-light levels of the
object viewed into numbers, which are immediately relayed back to earth (via a relay satellite)
and reconstructed into an image. Infrared and radar imagery are also transmitted in real-time.
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