Stratospheric Aerosol and Gas Experiment
Encyclopedia
The Stratospheric Aerosol and Gas Experiment (SAGE) is a series of remote sensing
satellite instruments used to study the chemical composition of earth's atmosphere
. Specifically, SAGE has been used to study the Earth's ozone layer
and aerosols at the troposhere through the stratosphere
. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation
. This is achieved by observing sunrises and sunsets during a satellite orbit. Physically, the SAGE instruments measure ultraviolet/visible energy and this is converted via algorithms to determine chemical concentrations. SAGE data has been used to study the atmospheres aerosols, ozone, water vapor, and other trace gases.
A fourth instrument, SAGE III-ISS, is due to be installed on the International Space Station
in 2014.
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
satellite instruments used to study the chemical composition of earth's atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
. Specifically, SAGE has been used to study the Earth's ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
and aerosols at the troposhere through the stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...
. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation
Attenuation
In physics, attenuation is the gradual loss in intensity of any kind of flux through a medium. For instance, sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light and sound are attenuated by water.In electrical engineering and telecommunications, attenuation affects the...
. This is achieved by observing sunrises and sunsets during a satellite orbit. Physically, the SAGE instruments measure ultraviolet/visible energy and this is converted via algorithms to determine chemical concentrations. SAGE data has been used to study the atmospheres aerosols, ozone, water vapor, and other trace gases.
History
There has been 3 series of SAGE instruments.- SAGE I - Flew on the TBD satellite
- SAGE II - Flew on the Earth Radiation Budget Satellite (ERBS)
- SAGE III - Flew on a Meteor-3M satellite
A fourth instrument, SAGE III-ISS, is due to be installed on the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
in 2014.