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The Envisat (Environmental Satellite) satellite is an Earth-observing satellite built by the European Space Agency. It was launched on March 1, 2002 aboard an Ariane 5 into a Sun synchronous polar orbit at a height of 790 km (±10 km). It orbits the Earth in about 101 minutes with a repeat cycle of 35 days. It is the largest European satellite to date (late 2006), with total mass 8211kg.

Envisat carries an array of nine Earth-observation instruments that gather information about the earth (land, water, ice, and atmosphere) using a variety of measurement principles.

Several of the instruments are advanced versions of instruments that were flown on the earlier ERS-1 and ERS-2 missions and other satellites.
  • ASAR (Advanced Synthetic Aperture Radar) operating in C band can detect changes in surface heights with sub-millimeter precision.
  • MERIS (MEdium Resolution Imaging Spectrometer) measures the reflectance of the Earth (surface and atmosphere) in the solar spectral range (390 to 1040 nm) and transmits some 15 spectral bands back to the ground segment.
  • AATSR (Advanced Along Track Scanning Radiometer) can measure the temperature of the sea surface
  • RA-2 (Radar Altimeter 2) is a dual-frequency Nadir pointing Radar operating in the Ku band and S bands, it is used for measuring ocean topography, map/monitor sea ice and measure land heights.
  • MWR (Microwave Radiometer) for measuring water vapour in the atmosphere and give estimate the tropospheric delay for the Altimeter
  • DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) for orbit determination to within 10 cm or less
  • GOMOS (Global Ozone Monitoring by Occultation of Stars) looks to stars as they descend through the Earth's atmosphere and change color, which also tells a lot about the presence of gases such as O3 (ozone), and allows for the first time a space-based measurement of the vertical distribution of these trace gases.
  • MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) is a spectrometer
  • SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) compares light coming from the sun to light reflected by the Earth, which provides information on the atmosphere through which the earth-reflected light has passed.

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satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.
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Earth observation satellites are satellites specifically designed to observe Earth from orbit, similar to reconnaissance satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc.
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European Space Agency (ESA), established in 1974, is an inter-governmental organisation dedicated to the exploration of space, currently with 17 member states. Its headquarters are in Paris.
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March 1 is the 1st day of the year (2nd in leap years) in the Gregorian calendar. There are 0 days remaining.

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2002 by topic:
News by month
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Ariane 5

Ariane 5 mock-up
Fact sheet
Function Heavy launch vehicle
Manufacturer EADS Astrium for
ESA and Arianespace
Country of origin Europe
Size
Height 59 m (193 ft)
Diameter 5.4 m (17.
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sun-synchronous orbit (sometimes incorrectly called a heliosynchronous orbit) is a geocentric orbit which combines altitude and inclination in such a way that an object on that orbit passes over any given point of the Earth's surface at the same local solar time.
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A polar orbit is an orbit in which a satellite passes above or nearly above both poles of the planet (or other celestial body) it is orbiting on each revolution. It therefore has an inclination of (or very close to) 90 degrees to the equator.
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ORBit is a CORBA compliant Object Request Broker (ORB). The current version is called ORBit2 and is compliant with CORBA version 2.4. It is developed under the GPL license and is used as middleware for the GNOME project.
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EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001. Their greatest hit, their debut single "time after time", peaked at #13 in the Oricon singles chart.
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Minutes are the instant written record of a meeting or hearing. They often give an overview of the structure of the meeting, starting with a list of those present, a statement of the various issues before the participants, and each of their responses thereto.
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day (symbol: d) is a unit of time equivalent to 24 hours. It is not an SI unit but it is accepted for use with SI.[1] The SI unit of time is the second. The term comes from the Old English dæg.

Definitions

The day has several definitions.
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European Remote-Sensing satellite (ERS) was the European Space Agency's first Earth-observing satellite. It was launched on July 17, 1991 into a Sun synchronous polar orbit at a height of 782–785 km.
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Synthetic aperture radar (SAR) is a form of radar in which sophisticated post-processing of radar data is used to produce a very narrow effective beam. It can only be used by moving instruments over relatively immobile targets, but it has seen wide applications in remote sensing
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C band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4 to 8 GHz.[1]. It was the first frequency band allocated for commercial ground-to-satellite communications. A typical C-band satellite uses 3.7–4.
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MEdium Resolution Imaging Spectrometer (MERIS) is one of the main instruments on-board the European Space Agency (ESA)'s Envisat platform.

This instrument is composed of five cameras disposed side by side, each equipped with a pushbroom spectrometer.
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spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials.
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A radiometer is a device used to measure the radiant flux or power in electromagnetic radiation. Although the term is perhaps most generally applied to a device which measures infrared radiation, it can also be applied to detectors operating any wavelength in the electromagnetic
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The three-letter acronym SEA may refer to:
  • Scientists and Engineers for America, a pro-science political advocacy group.
  • Schoof-Elkies-Atkin algorithm
  • Seattle-Tacoma International Airport (IATA: SEA, ICAO: KSEA)
  • Sea Education Association

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Radar is a system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain.
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altimeter is an active instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth underwater.
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nadir (from Arabic ﻧـدﻳﺭ nadeer نظير nathir, "opposite") is the astronomical term for the point in the sky directly below the observer, or more precisely, the point in the sky with an
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The Ku band (pronounced "kay-yoo"; Kurtz-under band) is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 12 to 18 GHz
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The S band ranges from 2 to 4 GHz., crossing the imaginary boundary between UHF and SHF at 3.0 GHz. It is part of the microwave band of the electromagnetic spectrum.
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Earth's oceans
(World Ocean)
  • Arctic Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Pacific Ocean
  • Southern Ocean
An ocean (from Ωκεανός, Okeanos
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Topography (Greek topos, "place", and graphia, "writing") is the study of Earth's surface features or those of planets, moons, and asteroids.

In a broader sense, topography is concerned with local detail in general, including not only relief but also
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Sea ice is formed from ocean water that freezes. Because the oceans consist of saltwater, this occurs at about -1.8 °C (28.8 °F).

Sea ice may be contrasted with icebergs, which are chunks of ice shelves or glaciers that calve into the ocean.
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Microwaves are electromagnetic waves with wavelengths shorter than one meter and longer than one millimeter, or frequencies between 300 megahertz and 300 gigahertz.
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A radiometer is a device used to measure the radiant flux or power in electromagnetic radiation. Although the term is perhaps most generally applied to a device which measures infrared radiation, it can also be applied to detectors operating any wavelength in the electromagnetic
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Water vapor or water vapour (see spelling differences), also aqueous vapor, is the gas phase of water. Water vapor is one state of the water cycle within the hydrosphere.
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