Electro-optical "intelligence" involves the acquisition of data from the portion of the electromagnetic spectrum of wavelengths that contains ultraviolet radiation, visible light, and infrared radiation.
The term intelligence refers to the use to which the optical spectrum is put. Ultraviolet, visible, and infrared rays can be collected and analyzed for the information they contain. For example, the detection of infrared radiation—either via satellite or localized detection devices— can reveal the location and movements of humans and heat-generating machinery.
Other analyses can reveal information about the composition of the object that is emitting the radiation. For example, the exhaust of a missile can be detected and distinguished from the exhaust of a commercial aircraft.
Electro-optical analysis equipment most commonly includes forms of radiometers, spectrometers, lasers, and laser radar devices.
Radiometers such as the Advanced Very High Resolution Radiometer operated by the National Oceanographic and Atmospheric Administration, and the Multi-angle Imaging Spectro Radiometer operated by the National Aeronautics and Space Administration provide detailed views of the Earth's surface. For example, the removal of vegetation from an area due to clearing and/or construction is readily detected. While used predominantly for climate studies, these instruments may also provide detailed views that allow critical assessment of the industrial and/or military development in a surveyed area.
A laser radar sends out pulses of a laser beam. The beam, a constrained and narrow beam of light, will ultimately encounter an object and be reflected, still as a tightly organized beam. When the beam returns to the source, a detector can measure the time taken for the beam to travel to the object and return. The distance from the source to the object can be measured very accurately over extremely long distances (i.e., Earth to the Moon).
The United States Army's Pulsed Laser Vulnerability Test System (PLVTS) is a CO 2 laser that can be housed in a portable vehicle. The unit can be taken to whatever test or military site requires accurate radar measurements. The PLVTS has been used in the evaluation of the M-1 tank, Black Hawk helicopter, and various missile test launches.
Another aspect of electro-optical intelligence involves the use of cameras that can record information in both the visible and infrared spectra. Because the infrared emissions from objects occur at night as well as during the day, these cameras are capable of gathering information both in day time and at night. Such cameras have been used in high altitude "spy planes" and other reconnaissance aircraft to develop intelligence concerning ground operations shrouded by clouds associated with weather fronts or more permanently obscured by thick indigenous fog or pollution.
Similarly, visible and infrared imaging is incorporated into telescopes operated by the U.S. Space Command in Haleakala, Maui (TEAL BLUE) and Malabar, Florida (TEAL AMBER). The telescopes are used for the tracking of satellites orbiting the Earth (including reconnaissance satellites) and those that are deeper in space.
█ FURTHER READING:
Gaffney, Timothy, R. Secret Spy Satellites: America's Eyes in Space. Berkeley Heights, NJ: Enslow Publishers Inc.,2000.
Kupperberg, Paul. Spy Satellites (The Library of Satellites). New York: Rosen Publishing Group, 2003.
Institute for Defense Studies and Analysis. "Shaping the Land Battle through Remote Sensing and Satellite-Imagery." JNU Campus. February, 2000. < http://www.idsa.org/an-feb00-5.html >(26 December 2002).
EM Wave Scanners
Infrared Detection Devices
Laser Listening Devices
LIDAR (Light Detection and Ranging)
Satellites, Non-Governmental High Resolution