Fengyun
Fengyun (FY) ( Chinese 風雲 / 风云 , wind and clouds ) is the name of a series of Chinese weather satellites that have been brought around the earth in polar or geosynchronous orbits since 1988 .
The satellites of the FY-1 series are stationed in a polar, sun-synchronous orbit, the satellites of the FY-2 series in a geostationary orbit. The meteorological satellites provide data for oceanography, agriculture and forestry, hydrology, aviation and shipping, environmental and disaster control and national defense. The latest satellites are able to provide data around the clock and in all weather conditions. B. about storms, rains, thunderstorms and hailstorms. In addition, they monitor the development of sandstorms and can provide measurements of air quality.
The series became known on January 11, 2007 when Fengyun-1C was destroyed by a Chinese anti-satellite missile test in orbit.
technology
Fengyun 1
The satellites Fengyun-1A and 1B were cuboid satellites with a size of 1.4 m × 1.4 m base. The height of Fengyun-1A was 1.2 m and Fengyun-1B 1.8 m. Fengyun 1C / D were approximately 2 m x 2.00 m x 2.21 m in size. The three-axis stabilized satellites were supplied with energy via two 3.5 m long solar cell booms with a total of 800 W and nickel-cadmium batteries . The mass of the satellites increased from 750 kg for Fengyun-1A to 960 kg for Fengyun-1D . Fengyun-1A and -1B were equipped with a five-channel radiometer . A further developed ten-channel radiometer was used for Fengyun-1C and -1D. This had a resolution of 1.1 km per pixel and a swath width of 2860 km. The transmission of the recordings took place in the same format as with the NOAA satellites and with Fengyun 1A / B on a frequency of 137 MHz, while Fengyun 1C / D transmitted on 1700.42 MHz (data rate is 1.3308 Mbps with PSK modulation ).
| channel | Spectral range | Color range | task |
|---|---|---|---|
| 1 | 0.58 µm to 0.68 µm | Yellow to red | Differentiation from other vegetation |
| 2 | 0.72 µm to 1.10 µm | Red to near infrared | at the maximum of the chlorophyll reflection, for vitality studies of plants |
| 3 | 3.50 µm to 3.90 µm | Infrared | Representation of hot spots |
| 4th | 10.3 µm to 11.3 µm | Thermal infrared | thermal radiation of the earth |
| 5 | 11.5 µm to 12.5 µm | Thermal infrared | thermal radiation of the earth |
| 6th | 1.58 µm to 1.64 µm | Near infrared | Separation of snow and ice |
| 7th | 0.43 µm to 0.48 µm | blue | Representation of the sea color |
| 8th | 0.48 µm to 0.53 µm | Blue to green | Representation of the sea color |
| 9 | 0.53 µm to 0.58 µm | Green to yellow | Representation of the sea color |
| 10 | 0.90 µm to 0.965 µm | Near infrared | Representation of ferrous rock and water vapor |
Fengyun 2
The satellites of the Fengyun-2 series are spin-stabilized, geostationary satellites of cylindrical appearance with a diameter of 2.1 m and a height of 2.1 m (4.5 m with antennas). The payload consists of a radiometer in the visible and infrared range and transmission systems in the S and UHF bands. The radiometer has a resolution of 1.25 km in the visible and 5 km in the infrared range. The take-off mass is between 1250 kg (FY-2B) and 1380 kg (FY-2C). The first satellite of the series was lost on April 2, 1994 when the CZ-3 launch vehicle caught fire on the launch pad and exploded.
Fengyun 3
The newer Fengyun-3 series is intended to replace the weather satellites of the Fengyun-1 series, both of which are stationed on polar sun-synchronous orbits. They have been in development since 1998 and will be used from 2008. The three-axis stable satellites are equipped with eleven instruments (including optical radiometers, infrared spectrometers, microwave thermometers and hygrometers and UV detectors for measuring the ozone layer and radiation meters). The takeoff weight is given as 2,450 kg. The optical sensors have a swath width of 2,400 km and a resolution of 250 m. They have two X-band (one for real-time transmission ) and one L-band (also real-time) transmitter for data transmission .
Fengyun 4
The newer Fengyun 4 series is intended to replace the Fengyún 2 series weather satellites, which are stationed on geostationary orbits. The satellites have a mass of 5300 kg. Fengyun-4A was launched on December 10, 2016.
Previous satellites
| begin | satellite | Launcher | orbit | in action |
|---|---|---|---|---|
| September 6, 1988 | Fengyun-1A | LM-4A | SSO | No (lifetime only 38 days) |
| 3rd September 1990 | Fengyun-1B | LM-4A | SSO | No (lifespan about 1 year) |
| June 10, 1997 | Fengyun-2A | LM-3 | GEO 105 ° E | No (lifetime 3 years, but failed several times in the meantime) |
| May 10, 1999 | Fengyun-1C | LM-4B | SSO | Destroyed by anti-satellite tests in 2007 |
| June 25, 2000 | Fengyun-2B | LM-3 | GEO 105 ° E | No (lifetime 3 years) |
| May 15, 2002 | Fengyun-1D | LM-4B | SSO | Yes |
| October 19, 2004 | Fengyun-2C | LM-3A | GEO 105 ° E | No ( steered into a cemetery orbit on December 13, 2014 ) |
| August 12, 2006 | Fengyun-2D | LM-3A | GEO 86.5 ° E | Yes |
| May 27, 2008 | Fengyun-3A | LM-4C | SSO | Yes |
| December 23, 2008 | Fengyun-2E | LM-3A | GEO | Yes |
| November 4, 2010 | Fengyun-3B | LM-4C | SSO | Yes |
| January 13, 2012 | Fengyun-2F | LM-3A | ||
| 23rd September 2013 | Fengyun-3C | LM-4C | ||
| December 10, 2016 | Fengyun-4A | LM-3B | GEO | |
| November 14, 2017 | Fengyun-3D | LM-4C | in preparation |
Individual evidence
- ↑ FY-1 in the Encyclopedia Astronautica (English)
- ↑ Radio observation ( memento from October 6, 2010 in the Internet Archive )
- ↑ Fengyún-1D at satellites AG ( Memento from July 4, 2007 in the Internet Archive )
- ↑ FY-2 in the Encyclopedia Astronautica (English)
- ↑ FY-3 in the Encyclopedia Astronautica (English)
- ↑ Gunter Krebs: FY 4A, 4B, 4C, 4D, 4E, 4F. In: Gunter's Space Page. October 27, 2016, accessed October 28, 2016 .