# Weather Satellites

This course gives an overview of the current weather satellite systems in operation today and studies other satellites of the same series that were launched and operated in the past.

## Overview

The 1960s heralded the first weather satellites and quickly proved their usefulness. By the 1970s clear trends were already established with the USA settling on the use of both Geostationary and Polar orbiting satellites. During this period, the European Space Agency (ESA) developed their own series of satellites, the Meteosats which were geostationary. Other countries later joined in to develop and launch their own systems.

### Current Coverage

For the past decade or even more, the configuration of operational satellites has been fairly stable. It consists of a set of equatorial geostationary satellites giving complete coverage of the entire globe and then a further set of polar orbital satellites that typically yield global coverage twice a day, twelve hours apart.
There are usually five geostationary satellites, two from the US, covering that region, one from Europe covering that slice of the globe and then one from India, and finally one from Japan covering their respective sectors of the Earth. These satellites generally give a full scan of the Earth's disk every 30 minutes or better.
The main drawback with geostationary satellites is that coverage at both polar regions is almost non-existent due to the very low angle of viewing.
A pair of polar orbiting satellites have been provided for many years by the NOAA (USA) agency. These make up for the lack of coverage by the geostationary satellites. This dataset goes back many years.

## Meteosat

The are series of geostationary satellites launched by the European Space Agency. There have been two generations of satellites with the current fleet being the Meteosat Second Generation (MSG).
In general the meteosat series of satellites have been placed at 0$^0$longitude over Africa and provide a permanent view of the disk of the Earth centered on Africa and including Europe, parts of the eastern Atlantic and western Russia, Middle East and corresponding geographic co-ordinates in the Southern Hemisphere.
As the satellites either failed or went out of operation, they were moved out of these orbital locations to safety or in some cases, the satellites were leased for a few years to other agencies and moved to locations over the Indian Ocean for example.
The operational Meteosat program was transferred from ESA in 1986 to the Eumetsat organization.

### Capabilities and Instruments

The first generation series had approximately 5 km resolution and scans in the Infrared and Water Vapor channels and 2.5 km in Visible wavelengths. The full Earth disk was scanned roughly every 30 minutes.
In the second generation series the resolution has been improved to 3km and a high resolution mode of 1 km. Scanning frequency is now every 15 mins. The MSG has a new multispectral imager called the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and this has 12 spectral channels instead of 3 as in the previous system.
| Imaging Band | Visible (VIS) | Water Vapor (WV) | Infrared (IR) |
| Spectral range | 0.45 - 1.0 μm | 5.71 - 7.1 μm | 10.5 - 12.5 μm |
| Resolution at nadir | 2.5 km | 5.0 km | 5.0 km |
| Scanning Frequency | 30 mins | 30 mins | 30 mins |

### Series
#### Meteosat First Generation

| Name | Launched & Lifetime | Located Over | Channels |
| Meteosat-1 | Sep 1977 - Oct 1979 | Africa, 0° longitude | IR, Vis, WV |
| Meteosat-2 | 1981 - 1991 | Africa, 0° longitude | IR, Vis, WV |
| Meteosat-3 | 1988-1995 | Africa, 0° longitude | IR, Vis, WV |
| Meteosat-4 | 1989 - 1995 | Africa, 0° longitude | IR, Vis, WV |
| Meteosat-5 | 1991 - 2007 | Africa, 10°W longitude | IR, Vis, WV |
| Meteosat-6 | 1993 - 2006 | Africa, 0° longitude | IR, Vis, WV |
| Meteosat-7 | 1997 - 2008 (planned) | Africa, 0° longitude | IR, Vis, WV |

#### Meteosat Second Generation (MSG)

This is a significantly enhanced follow-on system to the previous generation of Meteosat and is designed to last until 2018.
| Name | Launched | Status | Located Over | Channels |
| Meteosat-8 | Jan 29, 2004 | Operational | Africa | IR, Vis, WV |
| Meteosat-9 | Dec 21, 2005 | Operational | Africa | IR, Vis, WV |

## NOAA Weather Satellites

There are a series of polar orbiting satellites launched by NOAA. They are usually placed in an orbit inclined at 89$^°$ to equatorial plane at an altitude of approximately 800 km, giving an orbital period of about 90 minutes. At this inclination, the orbit processes about the globe and evidently covers the entire Earth every x days.
The most recent is the Suomi National Polar-orbiting Partnership satellite operated by NOAA and launched in 2011.

### Capabilities and Instruments

This series has approximately 1 km resolution and scans in the Infrared and Visible wavelengths. The main instrument is the AVHRR scanner. The improved resolution comes about as a result of a much lower orbit (~800km) as opposed to the 36,000 km for geostationary orbits.

### Series

| Name | Launched | Status | Scanner |
| NOAA-17 | Jan 29, 2004 | Operational | AVHRR (??) |
| NOAA-18 | Dec 21, 2005 | Operational | AVHRR (??) |

## GOES Weather Satellites

These are Geostationary Operational Environmental Satellite (GOES) system developed by the NASA and NOAA. There have been two main series, GOES and GOES-NEXT. The GOES satellites are operated in pairs nominally called GOES-East at 75$^0$ longitude and GOES-West at 135$^0$ longitude in order to give full coverage of the continuous US.
The GOES series satellites were designated by a letter until launch and then when operational were assigned a number. For example GOES-K was renamed GOES-10 upon reaching orbit.
The first GOES generation of satellites was launched in Oct, 1975 until 1994, when the second generation[factual?] of GOES I-M was introduced. GOES-15 is at right from 2011.

### Capabilities and Instruments

This series has approximately 1 km resolution and scans in the Infrared and Visible wavelengths. It scans the full disk of the Earth roughly every 30 minutes.

### Series
#### First Generation

| Name | Launched & Lifetime | Located Over | Channels |
| GOES-1 | Oct 1975 -Mar 1985 | Indian Ocean | ?? |
| GOES-2 | Jun 1977 - 1993 | 60$^0$ West | VISSR Scanner |
| GOES-3 | 1978 - 1993 | 60$^0$ West | VISSR Scanner |
| GOES-4 | Sep 1980 - Nov 1988 | 135$^0$ West | VISSR Scanner |
| GOES-5 | May 1981 - July 1990 | 75$^0$ West | VISSR Scanner |
| GOES-6 | Apr 1983 - 1989 | 136$^0$ West | VISSR Scanner |
| GOES-G | May 1986 lost in launch failure | N/A | N/A |
| GOES-7 | Apr 1983 - 12 April 2012 | 75$^0$ West | VISSR Scanner |

#### Second Generation

This series covers GOES I-M and are the current satellites of this series in use.
| Name | Launched & Lifetime | Located Over | Channels |
| GOES-8 | Apr 1994 - Present (??) | Indian Ocean | ?? |
| GOES-9 | May 1995 - 1998 | 135$^0$ West | ?? |
| GOES-10 | Apr 1997 - Present (??) | 105$^0$ West | ?? |
| GOES-11 | Apr 1983 - Present | ?? | ?? |

## US Military Weather Satellites

The US military has the Defense Meteorological Satellite Program (DMSP). This has been a long running program from the mid 1960s. The DMSP series are known as Low Earth Orbit (LEO) satellites. This class of orbit generally includes polar orbiting satellites.
* See Defense_Meteorological_Satellite_Program

## Russian

The Russians have launched numerous weather satellites over the years. Their weather satellites of interest are the Meteor-3M -polar orbiting satellites and GOMS geostationary series.

### GOMS

There was only one launch of satellite in this series which was GOMS-1 on 31st Oct 1994. Apparently the troubled spacecraft could not be put into use and the whole project was finally cancelled.

### Meteor
## Indian

Information on the Indian weather satellite program seems to be quite hard to determine, but they have had a space program going back to the 1980s and have tended to use multi-purpose satellites. The INSAT series for example can have different roles from one launch to the next, although presumably they satellite payloads are quite different.
The most recent India weather satellite appears to be geostationary INSAT 3A satellite launched on April 9th, 2003.
| Name | Launched & Lifetime | Located Over | Channels |
| INSAT-1A | 10th Apr 1982 - late 1982 | India, 74° East longitude | VHRR (Vis res 2.7km, IR res 11km, 30 mins) |
| INSAT-1B | 31st Aug 1983 - | India, 74° East longitude | VHRR (Vis res 2.7km, IR res 11km, 30 mins) |
| INSAT-1C | 21st Jul 1988 - | India, 94° East longitude | VHRR (Vis res 2.7km, IR res 11km, 30 mins) |
| INSAT-1D | 12th Jun 1990 - | India, 83.1° East longitude | VHRR (Vis res 2.7km, IR res 11km, 30 mins) |
| INSAT-2A | 12th Jun 1990 - | India, 74° East longitude | ?? |
| INSAT-2B | 22nd Jul 1993 - | India, 93.5° East longitude | ?? |
| INSAT-2D | 3rd Jun 1997 - | India, 74.1° East longitude | ?? |
| INSAT-2E | 2nd Apr 1999 - | India, 83° East longitude | VHRR (Vis res 2km, WV res 8km, ??) |
| INSAT-3A | 9th Apr 2003 | India, 93.5° East longitude | Vis, WV, IR |

## Japanese

The Japanese have operated geostationary satellites over Japan since 1977 when the first of the GMS series was launched. The main meteorological instrumentation was the Visible and Infrared Spin Scan Radiometer (VISSR)
| Name | Launched & Lifetime | Located Over | Channels |
| GMS-1 | 14th Jul 1977 | Pacific Ocean, 140° East longitude | VISSR |
| GMS-2 | 10th Aug 1981 - 2007? | Pacific Ocean, 140° East longitude | VISSR |
| GMS-3 | 3rd Aug 1984 - 2007? | Pacific Ocean, 140° East longitude | VISSR |
| GMS-4 | 6th Sep 1989 - 2007? | Pacific Ocean, 140° East longitude | VISSR |
| GMS-5 | 18th Mar 1995 - 2007? | Pacific Ocean, 140° East longitude | VISSR |

## Data Access
### Satellite Receiving and Data Centers

For the NOAA polar orbiting satellites, it is possible to get your own receiver and receive the data as it is broadcast as the satellite passes overhead daily.
For these receiving stations, the satellite may be programmed to dump data from disk from other areas down to them.
* USA (where??)
* Darmstadt, Germany
* Dundee, Scotland

## Glossary

* NOAA -National Oceanic and Atmospheric Administration

## Lectures

Many of these lectures introduce observational astronomies that have focused on Earth.
* Blue astronomy
* Cyan astronomy
* Earth
* Geostationary Operational Environmental Satellite‎s
* Green astronomy
* Infrared astronomy
* Lofting technology
* Meteor astronomy
* NIMBUS program
* NOAA satellites‎
* Optical astronomy
* Orange astronomy
* Planetary science
* Radiation astronomy detectors
* Radiation astronomy satellites
* Radio astronomy
* Red astronomy
* Submillimeter astronomy
* Ultraviolet astronomy
* Violet astronomy
* Visual astronomy
* X-ray astronomy
* Yellow astronomy

## Quizzes

* Blue astronomy/Quiz
* Cyan astronomy/Quiz
* Green astronomy/Quiz
* Infrared astronomy/Quiz
* Lofting technology/Quiz
* Meteor astronomy/Quiz
* Optical astronomy/Quiz
* Orange astronomy/Quiz
* Planetary science/Quiz
* Radiation detectors/Quiz
* Radiation satellites/Quiz
* Radio astronomy/Quiz
* Red astronomy/Quiz
* Submillimeter astronomy/Quiz
* Ultraviolet astronomy/Quiz
* Violet astronomy/Quiz
* Visual astronomy/Quiz
* X-ray astronomy/Quiz
* Yellow astronomy/Quiz

## See Also

Topic:Weather_satellites Topic:Remote_sensing