How Satellites Work: Satellites
are sent into orbit by rockets and receive signals from the Earth stations
in the form of high powered, high frequency (GHz range) signals.
The satellites then retransmit the signals back to the Earth stations.
Wavelength and frequency are inversely proportional and as wavelength increases, larger satellites are needed. There are different frequency bands and the most common are:
C-bands: 4-8 GHz frequency range
(translation of largest wavelengths) 2-3 meters in diameter
Ku-bands: 11-17 GHz frequency
range (shorter wavelengths; as small as 18 inches in diameter)
Ka-bands: 20-30 GHz frequency range (VERY small wavelength and diameter)
Pros: "It is easier to spy down
from a hill, than to spy up from a valley." (Yost 48)
The first satellites of the U.S. and
many of the satellites today are used primarily by the government to check
up on the Soviet Union. According to the SALT agreements of 1972,
this is perfectly legal. "Each country has the right to use its own
'national technical means' to verify the other side's compliance with the
Example: (Yost) The KH-11, built by the CIA and operated by the top-secret National Reconnaissance Office of Air Force Intelligence, is "the worlds finest satellite." It's 10 feet wide, 40-50 feet long, and weighs about 30,000 pounds. It has the ability to spot camouflage, see through clouds and see in the dark. It is able to discern small objects on the ground as small as an egg from hundreds of miles in outer space. It's purpose is to take pictures of missile tests at the Tyuratam launching site in the Soviet Union. (Yost)
An example of a non-government owned
satellite was launched at the end of April, 1999. The new satellite
was launched 420 miles into space from a California lauch pad.
This new satellite is different from the others because it has a focus so sharp that it can "tell the difference between a car and a truck" and even see white lines in a parking lot. So, this satellite is used to record cars, homes, roads, buildings, bridges, etc. and will be very useful for people such as miners, geographers and disaster-relief crews.
Though this satellite
does not have the capability to record individual people, there is still
a concern about privacy invasion. (Broad).
Additionally, the Terraserver is a comprehensive database of zoomable satellite images of much of the United States and Europe.
* Broad, William J. "Private
Spy in Space to Rival Military's." New York Times on the
Web 27 April 1999. 16 May 1999
* Yost, Graham. Spy-Tech. New York: Facts on File Publications, 1985.