NOAA-6, known as NOAA-A before launch, was an American operational

weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering the entire Earth asynchronously), or ge ...

for use in the National Operational Environmental Satellite System (NOESS) and for the support of the

Global Atmospheric Research Program The Global Atmospheric Research Program was a fifteen-year international research programme led by the World Meteorological Organization and the International Council of Scientific Unions. It began in 1967 and organised several important field exper ...

(GARP) during 1978-1984. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the

atmosphere of Earth The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

, its surface and

cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud co ...

, and the near-space environment.

Launch

It was launched into a

Sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

aboard of the

Atlas F The SM-65F Atlas, or Atlas-F, was the final operational variant of the Atlas missile, only differing from the Atlas E in the launch facility and guidance package used. It first flew on 8 August 1961, and was deployed as an operational ICBM between ...

S/N 25F

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...

on 27 June 1979 from

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USS General Harry Taylor (AP-145), USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in K ...

Vandenberg Space Launch Complex 3 Space Launch Complex 3 (SLC-3) is a launch site at Vandenberg Space Force Base that consists of two separate launch pads. SLC-3E (East) is currently used by the Atlas V launch vehicle, while SLC-3W (West) has been demolished. Launches from Vand ...

(SLC-3W),

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Spacecraft

The satellite was based upon the DMSP Block 5D

satellite bus A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-d ...

developed for the

U.S. Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

, and it was capable of maintaining an Earth-pointing accuracy of better than ± 0.1° with a motion rate of less than 0.035 degrees/second.

Instruments

Primary sensors included the Advanced Very High Resolution Radiometer (AVHRR/1) for global cloud cover observations, and the TIROS Operational Vertical Sounder (TOVS) suite for atmospheric temperature and water profiling. Secondary experiments consisted of a Space Environment Monitor (SEM) measuring

proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

and

electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no kn ...

fluxes, and the Data Collection and Platform Location System (DCPLS) for relaying data from balloons and ocean buoys for the

Argos Argos most often refers to: * Argos, Peloponnese, a city in Argolis, Greece ** Ancient Argos, the ancient city * Argos (retailer), a catalogue retailer operating in the United Kingdom and Ireland Argos or ARGOS may also refer to: Businesses ...

system. The TOVS suite consists of three subsystems: the High Resolution Infrared Radiation Sounder 2 (HIRS/2), the Stratospheric Sounding Unit (SSU), and the

Microwave Sounding Unit The microwave sounding unit (MSU) was the predecessor to the Advanced Microwave Sounding Unit (AMSU). The MSU was first launched aboard the TIROS-N satellite in late 1978 and provided global coverage (from Pole to Pole). It carries a 4-channel mic ...

(MSU).

Advanced Very High Resolution Radiometer (AVHRR/1)

The NOAA-6

Advanced Very High Resolution Radiometer The Advanced Very-High-Resolution Radiometer (AVHRR) instrument is a space-borne sensor that measures the reflectance of the Earth in five spectral bands that are relatively wide by today's standards. AVHRR instruments are or have been carried b ...

(AVHRR/1) was a four-channel scanning radiometer capable of providing global daytime and nighttime sea-surface temperature and information about ice, snow, and clouds. These data were obtained on a daily basis for use in weather analysis and forecasting. The multispectral radiometer operated in the scanning mode and measured emitted and reflected radiation in the following spectral intervals: channel 1 (

visible Visibility, in meteorology, is a measure of the distance at which an object or light can be seen. Visibility may also refer to: * A measure of turbidity in water quality control * Interferometric visibility, which quantifies interference contrast ...

), 0.55 to 0.90 micrometer (µm); channel 2 (

near infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

), 0.725 µm to detector cutoff around 1.1 µm; channel 3 (IR window), 3.55 to 3.93 µm; and channel 4 (IR window), 10.5 to 11.5 µm. All four channels had a spatial resolution of 1.1 km, and the two IR-window channels had a thermal resolution of 0.12

Kelvin The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...

at 300 Kelvin. The AVHRR was capable of operating in both real-time or recorded modes. Real-time or direct readout data were transmitted to ground stations both at low (4 km) resolution via automatic picture transmission (APT) and at high (1 km) resolution via

high-resolution picture transmission Weather satellite pictures are often broadcast as high-resolution picture transmissions (HRPTs), color high-resolution picture transmissions (CHRPTs) for Chinese weather satellite transmissions, or advanced high-resolution picture transmissions ( ...

(HRPT). Data recorded on board were available for processing in the NOAA central computer facility. They included global area coverage (GAC) data, with a resolution of 4 km, and local area coverage (LAC), that contained data from selected portions of each orbit with a 1-km resolution. Identical experiments were flown on other spacecraft in the TIROS-N/NOAA series.

TIROS Operational Vertical Sounder (TOVS)

The TOVS consisted of three instruments: the High-resolution Infrared Radiation Sounder modification 2 (HIRS/2), the Stratospheric Sounding Unit (SSU), and the Microwave Sounding Unit (MSU). All three instruments were designed to determine radiances needed to calculate temperature and humidity profiles of the atmosphere from the surface to the

stratosphere The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...

(approximately 1 mb). The HIRS/2 instrument had 20 channels in the following spectral intervals: channels 1 through 5 , the 15-micrometer (µm) CO₂ bands (15.0, 14.7, 14.5, 14.2, and 14.0 µm); channels 6 and 7, the 13.7- and 13.4-µm CO₂/H₂O bands; channel 8, the 11.1-µm window region; channel 9, the 9.7-µm

ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

band; channels 10, 11, and 12, the 6-µm

water vapor (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous pha ...

bands (8.3, 7.3, and 6.7 µm); channels 13 and 14, the 4.57- and 4.52-µm N₂O bands; channels 15 and 16, the 4.46- and 4.40-µm CO₂/N₂O bands; channel 17, the 4.24-µm CO₂ band; channels 18 and 19, the 4.0- and 3.7-µm window bands; and channel 20, the 0.70-µm

visible region The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' or simply light. A typical human eye will respond to wav ...

. The SSU instrument was provided by the British Meteorological Office (

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

). It was similar to the Pressure-Modulated Radiometer (PMR) flown on

Nimbus 6 Nimbus 6 (also called Nimbus G) was a meteorological satellite. It was the sixth in a series of the Nimbus program. Launch Nimbus 6 was launched on June 12, 1975, by a Delta rocket from Vandenberg Air Force Base, California, United States. The ...

. The SSU operated at three 15.0-µm channels using selective absorption, passing the incoming radiation through three pressure-modulated cells containing CO². The MSU instrument was similar to the Scanning Microwave Spectrometer (SCAMS) flown on Nimbus 6. The MSU had one channel in the 50.31-GHz window region and three channels in the 55-GHz oxygen band (53.73, 54.96, and 57.95 GHz) to obtain temperature profiles which were free of cloud interference. The HIRS/2 had a

field of view The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation. Humans a ...

(FOV) 30 km in diameter at

nadir The nadir (, ; ar, نظير, naẓīr, counterpart) is the direction pointing directly ''below'' a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface. The direc ...

, whereas the MSU had a FOV of 110 km in diameter. The HIRS/2 sampled 56 FOVs in each scan line about 2250 km wide, and the MSU sampled 11 FOVs along the swath with the same width. Each SSU scan line had 8 FOVs with a width of 1500 km. This experiment was also flown on other TIROS-N/NOAA series spacecraft.

Data Collection and Platform Location System (DCPLS)

The DCPLS on NOAA-6, also known as

, was designed and built in France to meet the meteorological data needs of the United States and to support the Global Atmospheric Research Program (GARP). The system received low-duty-cycle transmissions of meteorological observations from free-floating balloons, ocean buoys, other satellites, and fixed ground-based sensor platforms distributed around the globe. These observations were organized on board the spacecraft and retransmitted when the spacecraft came within range of a Command and Data Acquisition (CDA) station. For free-moving balloons, the Doppler frequency shift of the transmitted signal was observed to calculate the location of the balloons. The DCPLS was expected, for a moving sensor platform, to have a location accuracy of 3 to 5 km, and a velocity accuracy of 1.0 to 1.6 m/s. This system had the capability of acquiring data from up to 4000 platforms per day. Identical experiments were flown on other spacecraft in the TIROS-N/NOAA series. Processing and dissemination of data were handled by

CNES The (CNES; French: ''Centre national d'études spatiales'') is the French government space agency (administratively, a "public administration with industrial and commercial purpose"). Its headquarters are located in central Paris and it is und ...

Toulouse Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Par ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

Space Environment Monitor (SEM)

The SEM was an extension of the solar proton monitoring experiment flown on the ITOS spacecraft series. The object was to measure

flux,

flux density, and energy spectrum in the

upper atmosphere Upper atmosphere is a collective term that refers to various layers of the atmosphere of the Earth above the troposphere and corresponding regions of the atmospheres of other planets, and includes: * The mesosphere, which on Earth lies between the ...

. The experiment package consisted of three detector systems and a data processing unit. The Medium Energy Proton and Electron Detector (MEPED) measured protons in five energy ranges from 30 keV to >2.5 MeV; electrons above 30, 100, and 300 keV; protons and electrons (inseparable) above 6 MeV; and omni-directional protons above 16, 36, and 80 MeV. The High-Energy Proton Alpha Telescope (HEPAT), which had a 48° viewing cone, viewed in the anti-Earth direction and measured protons in four energy ranges above 370 MeV and

alpha particle Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produce ...

s in two energy ranges above 850 MeV/

nucleon In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number (nucleon number). Until the 1960s, nucleons were ...

. The Total Energy Detector (TED) measured electrons and protons between 300 eV and 20 keV.

Science objectives

* Day and night observation of global cloud cover. * Observation of atmospheric water/temperature profile. * Monitoring particle flux in the near-Earth environment.

Mission

NOAA-6 performed monitoring of ice and snow cover, agriculture, oceanography, volcanism, ozone and the space environment, in addition to its regular meteorological observations. The HIRS/2 instrument failed on 19 September 1983, and in early 1984, only one to two NOAA-6 passes were taken per day due to priorities for

NOAA-7 NOAA-7, known as NOAA-C before launch, was an American operational weather satellite for use in the National Operational Environmental Satellite System (NOESS) and for the support of the Global Atmospheric Research Program (GARP) during 1978-19 ...

and

NOAA-8 NOAA-8, known as NOAA-E before launch, was an American weather satellite operated by the National Oceanic and Atmospheric Administration (NOAA) for use in the National Environmental Satellite Data and Information Service (NESDIS). It was first ...

data. However, when NOAA-8 failed in late June 1984, NOAA-6 was returned to full operational status to continue to provide morning orbit operational data. It was returned to operational status after NOAA-8 failed in June 1984, and continued to return data until its decommissioning on 31 March 1987.

Gallery

Image:Allen 07 aug 1980 1355Z N6.jpg,

Hurricane Allen Hurricane Allen was a rare and extremely powerful Cape Verde hurricane that affected the Caribbean, eastern and northern Mexico, and southern Texas in August 1980. The first named storm and second tropical cyclone of the 1980 Atlantic hurrican ...

in the

Yucatán Channel The Yucatán Channel or Straits of Yucatán (Spanish: ''Canal de Yucatán'') is a strait between Mexico and Cuba. It connects the Yucatán Basin of the Caribbean Sea with the Gulf of Mexico. It is just over wide and nearly deep at its deepest ...

7 August 1980 Image:Bonnie 16 aug 1980 1028Z N6.jpg, Hurricane Bonnie
16 August 1980 Image:Charley 23 aug 1980 1254Z N6.jpg,

Hurricane Charley Hurricane Charley was the first of four separate hurricanes to impact or strike Florida during 2004, along with Hurricane Frances, Frances, Hurricane Ivan, Ivan and Hurricane Jeanne, Jeanne, as well as one of the strongest hurricanes ever to ...

23 August 1980 Image:Georges 08 sep 1980 1158Z N6.jpg,

Hurricane Georges Hurricane Georges () was a powerful and long-lived Cape Verde Category 4 hurricane which caused severe destruction as it traversed the Caribbean and Gulf of Mexico in September 1998, making eight landfalls along its path. Georges was the sevent ...

8 September 1980 Image:Frances 09 sep 1980 1003Z N6.jpg,

Hurricane Frances Hurricane Frances was the second most intense tropical cyclone in the Atlantic during 2004 and proved to be very destructive in Florida. It was the sixth named storm, the fourth hurricane, and the third major hurricane of the 2004 Atlantic hu ...

9 September 1980

References

External links

NOAA-6 Satellite Position
{{Orbital launches in 1979 Weather satellites of the United States Derelict satellites orbiting Earth National Oceanic and Atmospheric Administration Spacecraft launched by Atlas rockets Spacecraft launched in 1979