Platforms: TOPEX/POSEIDON
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Launched in 1992, TOPEX/Poseidon is a joint venture between CNES and NASA that measured ocean surface topography to an accuracy of 4.2 cm, enabled scientists to forecast the 1997-1998 El Nino, and improved understanding of ocean circulation and its effect of global climate. While a 3-year prime mission was planned, with a 5-year store of expendables, TOPEX/Poseidon delivered an astonishing 13+ years of data from orbit. The mission ended in January 2006. | Launched in 1992, TOPEX/Poseidon is a joint venture between CNES and NASA that measured ocean surface topography to an accuracy of 4.2 cm, enabled scientists to forecast the 1997-1998 El Nino, and improved understanding of ocean circulation and its effect of global climate. While a 3-year prime mission was planned, with a 5-year store of expendables, TOPEX/Poseidon delivered an astonishing 13+ years of data from orbit. The mission ended in January 2006. | ||
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Objectives | Objectives | ||
* Three-year global view of Earth's oceans | * Three-year global view of Earth's oceans | ||
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* Data coverage global between 66°N and 66°S latitude | * Data coverage global between 66°N and 66°S latitude | ||
* Data availability through NASA/JPL and CNES | * Data availability through NASA/JPL and CNES | ||
| + | == Спутник == | ||
| + | {| | ||
| + | |[[File:topex-poseidon.jpg|thumb|300px]] | ||
| + | | | ||
| + | In those 13 years, it: | ||
| + | * Measured sea levels with unprecedented accuracy to better than 5 cm | ||
| + | * Continuously observed global ocean topography | ||
| + | * Monitored effects of currents on global climate change and produced the first global views of seasonal changes of currents | ||
| + | * Monitored large-scale ocean features like Rossby and Kelvin waves and studied such phenomena as El Nino, La Nina, and the Pacific Decadal Oscillation | ||
| + | * Mapped basin-wide current variations and provided global data to validate models of ocean circulation | ||
| + | * Mapped year-to-year changes in heat stored in the upper ocean | ||
| + | * Produced the most accurate global maps of tides ever | ||
| + | * Improved our knowledge of Earth's gravity field | ||
|} | |} | ||
== Результат == | == Результат == | ||
{| | {| | ||
| - | |[[File:wet. | + | |[[File:wet.gif|thumb|300px]] |
|This plot shows the mean wet troposphere correction during cycle 30 of the Topex/Poseidon mission, i.e. during the 10-day interval starting 7 July 1993. The mean correction during this time period was 156 mm, the maximum 454 mm, the minimum 0 mm. | |This plot shows the mean wet troposphere correction during cycle 30 of the Topex/Poseidon mission, i.e. during the 10-day interval starting 7 July 1993. The mean correction during this time period was 156 mm, the maximum 454 mm, the minimum 0 mm. | ||
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Latest revision as of 13:49, 3 December 2012
Launched in 1992, TOPEX/Poseidon is a joint venture between CNES and NASA that measured ocean surface topography to an accuracy of 4.2 cm, enabled scientists to forecast the 1997-1998 El Nino, and improved understanding of ocean circulation and its effect of global climate. While a 3-year prime mission was planned, with a 5-year store of expendables, TOPEX/Poseidon delivered an astonishing 13+ years of data from orbit. The mission ended in January 2006.
Objectives
- Three-year global view of Earth's oceans
- Improved understanding of ocean currents
- Improved forecasting of global climate
Mission
- Joint NASA-CNES program
- Launched August 10, 1992
- Launch Vehicle: Arianespace's Ariane 42P
- Launch Site: Centre Spatial Guyanais, Kourou, French Guiana
- Operations for 3-year prime mission, 6-year extended: JPL
- Orbit: 1336-km, circular, 66° inclination
- 10-day repeat of ground track (±1-km accuracy)
- Covers 95% of ice-free oceans every 10-days
Spacecraft
- Based on Fairchild's Multi-Mission Spacecraft bus
- Total mass: 2402 kg (5296 lbs)
- Single solar panel provides 3.4 kW of power
- 1.2 m (4 foot) high-gain antenna communicates through TDRSS
- Reaction wheels and torque rods maintain 3-axis stabilization and nadir pointing
- Hydrazine propellant system provides orbital maintenance
Payload/Sensors
- NASA dual-frequency (C- and Ku-band) altimeter and CNES single-frequency (Ku-band) solid-state altimeter measures height above sea
- NASA microwave radiometer measures water vapor along altimeter path to correct for pulse delay
- NASA Global Positioning System demonstration receiver provides precise orbit ephemeris data
- NASA laser retroreflector array works with ground stations to track satellite and calibrate and verify altimeter measurements.
- CNES DORIS Doppler tracking antenna receives ground signals for precise orbit determination, satellite tracking, and ionospheric correction data for CNES altimeter
Data
- Sea-level measurement accuracy 4.2 cm (1.7 inch)
- Data coverage global between 66°N and 66°S latitude
- Data availability through NASA/JPL and CNES
Спутник
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In those 13 years, it:
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Результат
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This plot shows the mean wet troposphere correction during cycle 30 of the Topex/Poseidon mission, i.e. during the 10-day interval starting 7 July 1993. The mean correction during this time period was 156 mm, the maximum 454 mm, the minimum 0 mm. |
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Источники
Описание: http://sealevel.jpl.nasa.gov/missions/topex/ Изображения: http://space.skyrocket.de/doc_sdat/topex-poseidon.htm, http://iliad.gsfc.nasa.gov/opf/algorithms/wet_topex.html, http://en.wikipedia.org/wiki/TOPEX/Poseidon
