CFOSat

from Wikipedia, the free encyclopedia
CFOSat
Type: Earth observation satellite
COSPAR-ID : 2018-083A
Mission dates
Dimensions: 650 kg
Size: 1.4 × 1.4 × 1.2 m
Begin: October 29, 2018 at 12:43 AM UTC
Starting place: Jiuquan , ramp 94 of launch complex 43
Launcher: Long march 2C
Orbit data
Track height: 520 km
Orbit inclination : 97.5 °

CFOSat (Chinese-French Oceanography Satellite) is a marine research satellite of the Chinese CNSA and French CNES . The joint project was launched in 2007, and in 2009 it was officially approved on the Chinese side by the National Defense Agency for Science, Technology and Industry (the Chinese space agency CNSA is a department within this agency). CFOSat is the most important space cooperation between the two countries to date.

It was launched into sun-synchronous orbit on October 29, 2018 at 00:43 UTC with a Langer March 2C launcher from the Jiuquan rocket launch site (along with five cubesats ) . The satellites brought into orbit are four nano-sats from Spacety Aerospace Corporation . The six-kilogram Xiaoxiang-1, the eight-kilogram Tongchuan-1, the eight-kilogram Xinghe and the eight-kilogram Changshagaoxin, as well as the two-kilogram technology satellite CubeBel-1 from the Belarusian State University.

The three-axis stabilized satellite is equipped with two scatterometers . The two instruments come from China and France. These are SWIM (Surface Waves Investigation and Monitoring), a wave scatterometer supplied by CNES (built by Thales Alenia Space ), and SCAT, also a scatterometer, which is supposed to measure the wind fields over the oceans. This instrument comes from the CNSA. Both scatterometer are Ku-band - radars that scan the frequency range from 13.2 to 13.6 gigahertz. The data obtained on wind currents and wave heights in the oceans will be used to research the interaction between the seas and the atmosphere and, among other things, improve the long-term forecast of tropical cyclones. It was built on the basis of the CAST2000 satellite bus from DFH-Satellite Corporation and has a planned service life of three years.

Instruments

The SWIM radar uses a rotating antenna that is 90 cm in diameter and has six beams (0 °, 2 °, 4 °, 6 °, 8 ° and 10 ° from the nadir) that rotates once every 11 seconds. With each pass of CFOSat, the SWIM radar measures the wave and wind conditions over a 180-kilometer-wide strip, so that the same area of ​​the earth is recorded once every 13 days. The accuracy at wave height in the nadir is better than 10% or 50 cm (maximum), the accuracy at the wind speed is approx. ± 2 m / s or 10% (whichever is greater), the observable wavelengths of Waves (70 to 500 m) with an accuracy of 10 to 20%. A spatial resolution of 35 m is achieved through appropriate onboard data processing, with the radar lobes each having a diameter of 18 km on the ground.

SCAT is a Ku-band RFSCAT with HH and VV polarizations. Two 1.2 m × 0.4 m waveguide slot antennas are mounted on the satellite. The antenna rotates about six times per minute. A TWTA (Traveling Wave Tube Amplifier) ​​delivers 120 W pulse-modulated output power. The expected wind speed accuracy was originally 2 m / s or 10% in the wind speed range from 4 to 24 m / s. After more than eight months of tests in orbit, however, it was confirmed that the accuracy actually achieved is 1.5 m / s. The wind direction accuracy is ± 20º within the 360º wind direction range and the ground geolocation accuracy is <5 km. The swath width of the instrument is more than 1000 km.

In January 2020, the first meeting of the Chinese CFOSat scientific team took place in Beijing, with over 70 participants from 37 institutions interested in the data, and in February 2020 CFOSat was officially handed over to the Chinese Ministry of Land Resources (自然资源 部), where the National Center for Oceanographic Satellite Applications (国家 卫星 海洋 应用 中心) acts as the operator of the satellite.

Web links

Individual evidence

  1. ↑ a b c 中法 海洋 卫星 正式 在 轨 交付. In: cnsa.gov.cn. February 24, 2020, accessed March 1, 2020 (Chinese).
  2. ↑ a b The Orion: Cooperation in Orbit with CFOSat , accessed on January 5, 2019
  3. ↑ Spaceflight Now: China-France Oceanography Satellite launches on research mission - Spaceflight Now , accessed January 5, 2019
  4. ↑ a b eoportal: CFOSAT - eoPortal Directory - Satellite Missions , accessed on January 5, 2019
  5. ↑ CNES: Instrument , accessed January 5, 2019
  6. ↑ D. Hauser, D. Xiaolong, L. Aouf, C. Tison and P. Castillan, "Overview of the CFOSAT mission," 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, 2016, pp. 5789-5792. doi: 10.1109 / IGARSS.2016.7730512
  7. ↑ 第一 届 中法 海洋 卫星 中方 科学 团队 会议 在 北京 召开. In: nsoas.org.cn. January 21, 2020, accessed March 1, 2020 (Chinese).