EM 1110-2-2907
1 October 2003
b. Aerial Photography. The idea of mounting a camera on platforms above the
ground for a "birds-eye" view came about in the mid-1800s. In the 1800's there were few
objects that flew or hovered above ground. During the US Civil War, cameras where
mounted on balloons to survey battlefield sites. Later, pigeons carrying cameras were
employed (http://www2.oneonta.edu/~baumanpr/ncge/rstf.htm), a platform with obvious
disadvantages. The use of balloons and other platforms created geometric problems that
were eventually solved by the development of a gyro-stabilized camera mounted on a
rocket. This gyro-stabilizer was created by the German scientist Maul and was launched
in 1912.
c. First Satellites. The world's first artificial satellite, Sputnik 1, was launched on 4
October 1957 by the Soviet Union. It was not until NASA's meteorological satellite
TIROS 1 was launched that the first satellite images were produced
(http://www.earth.nasa.gov/history/tiros/tiros1.html). Working on the same principles as
the camera, satellite sensors collect reflected radiation in a range of spectra and store the
data for eventual image processing (see above, this chapter).
d. NASA's First Weather Satellites. NASA's first satellite missions involved study of
the Earth's weather patterns. TIROS (Television Infrared Operational Satellite) missions
launched 10 experimental satellites in the early 1960's in an effort to prepare for a per-
manent weather bureau satellite system known as TOS (TIROS Operating System).
TIROS-N (next generation) satellites currently monitor global weather and variations in
the Earth's atmosphere. The goal of TIROS-N is to acquire high resolution, diurnal data
that includes vertical profile measurements of temperature and moisture.
e. Landsat Program. The 1970's brought the introduction of the Landsat series with
the launching of ERTS-1 (also known as Landsat 1) by NASA. The Landsat program was
the first attempt to image whole earth resources, including terrestrial (land based) and
marine resources. Images from the Landsat series allowed for detailed mapping of land-
masses on a regional and continental scale.
(1) The Landsat imagery continues to provide a wide variety of information that is
highly useful for identifying and monitoring resources, such as fresh water, timberland,
and minerals. Landsat imagery is also used to assess hazards such as floods, droughts,
forest fire, and pollution. Geographers have used Landsat images to map previously un-
known mountain ranges in Antarctica and to map changes in coastlines in remote areas.
(2) A notable event in the history of the Landsat program was the addition of TM
(Thematic Mapper) first carried by Landsat 4 (for a summary of Landsat satellites see
tion as low as 30 m, a great improvement over the 70-m resolution of earlier sensors. The
gion of the spectrum.
(3) In the late 1970's, the regulation of Landsat was transferred from NASA to
NOAA, and was briefly commercialized in the 1980s. The Landsat program is now oper-
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