Sentinel-5P

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Sentinel-5P
Sentinel-5P
Type: Earth observation satellite
Operator: European space agencyESA ESA
COSPAR-ID : 2017-064A
Mission dates
Dimensions: 820 kg
Begin: October 13, 2017
Starting place: Plesetsk Cosmodrome
Launcher: Rockot KM
Flight duration: 7 years (planned)
Status: in operation
Orbit data
Rotation time : 101 min
Track height: 824 km
Orbit inclination : 98.74 °

Sentinel-5P (short for Sentinel-5 Precursor ; German: Guardian 5 precursor ) is in October 2017 under the Copernicus program of the ESA launched earth observation satellite . He monitors air pollution with a multi-channel spectrometer called “Tropomi”, built in the Netherlands . This closes parts of the data gap between the Envisat , which failed in 2012, and the Sentinel 5 mission planned for 2020 . The duration of the mission is set at seven years.

Mission objectives

ESA defined the objectives of the Tropomi / Sentinel-5P mission as follows:

"Measurement of the troposphere down to the earth's surface, for scientific research and to support services for society, with a sufficient spatial-temporal resolution of anthropogenic and natural emissions and atmospheric life cycles of the essential tropospheric pollutants ( ozone , nitrogen dioxide , carbon monoxide , formaldehyde and Sulfur dioxide ) and two major greenhouse gases (tropospheric ozone and methane ). In addition, aerosol particles are to be observed, which influence air quality and radiative forcing ( climate forcing ) regionally and globally. "

The Netherlands Institute for Space Research described the following mission objectives for Tropomi:

  • More precise delimitation of the strength, development and spatiotemporal variability of the sources of greenhouse gases and aerosols that affect air quality and the climate;
  • Understand the importance of radiative forcing through a better understanding of the processes that control the lifespan and distribution of methane, tropospheric ozone and aerosols;
  • Better assessment of long-term trends in the troposphere with reference to air quality and climate from regional to global level,
  • Develop and improve processes for modeling and data assimilation to support services such as air quality monitoring and prediction.

Technical data and orbit

Sentinel-5P is based on the Astrobus L 250 satellite bus from Astrium . He has S- and X-band -Kommunikationsantennen, three foldable solar modules with 1500  watts power output, a 156- Ah battery and hydrazine - engines for attitude control. 80 kg of fuel were carried. The scientific data is transmitted to the ground station in the X-band at a data rate of 310 Mbit / s .

The satellite is in a sun-synchronous orbit at an altitude of 824 km, with an orbit inclination of 98.74º and an equator crossing of the ascending node at around 1.30 p.m. local solar time . The orbital time is 101 minutes, and the time to return to the same point is 17 days.

Tropomi

Tropomi (original spelling TROPOMI , short for Tropospheric Monitoring Instrument , German: Tropospheric Monitoring Instrument ) is the only instrument on board Sentinel-5P. It is a spectrometer in the ultraviolet , human-visible and infrared light. The evaluation of the measurement data provides information about the atmospheric concentration and distribution of the substances defined in the mission objectives as well as bromine monoxide , glyoxal , water and clouds.

Tropomi measures the data of an area of ​​2600 km × 7 km once per second, from August 6, 2019 5.5 km. A 95% coverage in the range of 7 ° north to 7 ° south latitude and complete coverage of the rest of the earth's surface is achieved. The light is in accordance with the grating spectrometer principle in the spectral bands of ultraviolet (UV), visible light, near infrared (NIR) and short-wavelength infrared (SWIR, engl. Short-wave infrared ) cut and then measured by separate detectors. The measuring ranges are 270–320 nm for UV, 310–500 nm for visible light, 675–775 nm for NIR and 2305–2385 nm for SWIR.

The instrument consists of four main modules: One contains the telescope , UV / visible / NIR spectrometer and calibration unit , another the SWIR spectrometer with corresponding optics; there is also a control unit and a cooling module. The total mass of Tropomi is 220 kg and the power consumption is approx. 170 watts. About 140 gigabits of data are transmitted per earth orbit .

Tropomi was built by a joint venture of the Netherlands Space Office , the Royal Netherlands Meteorological Institute , the Netherlands Institute for Space Research , the Netherlands Organization for Applied Scientific Research and Dutch Space .

Tropomi data products

Level 1B data products (radiance) with the wavelength ranges used and the spatial resolution
product Wavelength range in nm Resolution in km
L1B_RA_BD1 270 - 300 (UV) 5.5 × 28
L1B_RA_BD2 300 - 320 (UV) 5.5 x 3.5
L1B_RA_BD3 320 - 405 (UVIS) 5.5 x 3.5
L1B_RA_BD4 405 - 500 (UVIS) 5.5 x 3.5
L1B_RA_BD5 675 - 725 (NIR) 5.5 x 3.5
L1B_RA_BD6 725 - 775 (NIR) 5.5 x 3.5
L1B_RA_BD7 2305-2345 (SWIR) 5.5 × 7
L1B_RA_BD8 2345-2385 (SWIR) 5.5 × 7

Based on the specific spectral signatures, the Level 2 products are modeled from the Level 1B products with the help of additional data ( ozone , nitrogen dioxide , carbon monoxide , formaldehyde , sulfur dioxide , methane and aerosols ). It should be noted that the spatial resolution of the satellite in the nadir range is usually higher than that in the models and tables used.

Preparations and course of the mission

The first major contract for Sentinel-5P was signed in July 2009 between ESA and the Dutch Ministry of Economic Affairs and Climate , which pledged 78 million euros for the construction of the Tropomi instrument. In December 2011, ESA selected Astrium UK as the main supplier of the satellite, in a contract worth 45.5 million euros. The satellite was completed in May 2014; then the spectrometer was installed.

Eurockot Launch Services , then a joint venture between Astrium and GKNPZ Khrunichev (now ArianeGroup and GKNPZ Khrunichev) , was commissioned with the launch of the satellite . The launch on board a Rockot rocket, initially planned for 2016 , finally took place on October 13, 2017. 79 minutes after taking off from the Plesetsk cosmodrome , Sentinel-5P reached its intended orbit. On October 18, the Tropomi control unit was activated, and on October 20, the first scientific data could be received without errors. The first pictures were published on December 1st, 2017.

Web links

Individual evidence

  1. ↑ a b c d e f Copernicus: Sentinel-5P , eoPortal Directory, accessed on November 5, 2017.
  2. ↑ Mission Objectives - Sentinel 5P Mission. ESA, accessed November 5, 2017 .
  3. ↑ a b Sentinel 5 precursor / TROPOMI. Netherlands Institute for Space Research , accessed November 5, 2017 .
  4. ↑ a b Sentinel 5 Data Sheet. (PDF) ESA, August 2013, accessed on November 5, 2017 .
  5. ↑ a b c Satellite Description - Sentinel 5P Mission. ESA, accessed November 5, 2017 .
  6. ↑ a b c TROPOMI: instrument. Archived from the original on May 24, 2011 ; Retrieved November 5, 2017 .
  7. ↑ a b S5P Mission Performance CentreLevel 1bReadme. Retrieved May 19, 2020 .
  8. ^ A b Agreement between the Netherlands and ESA signed for Sentinel-5 Precursor instrument. ESA, July 6, 2009, accessed November 5, 2017 .
  9. ↑ TROPOMI ATBD of the total and tropospheric NO2 data products. Retrieved May 19, 2020 .
  10. ↑ ESA selects Astrium to build Sentinel-5 Precursor satellite. ESA, December 8, 2011, accessed November 5, 2017 .
  11. ↑ Platform brings air monitoring a step closer. ESA, May 27, 2014, accessed September 6, 2014 .
  12. ↑ ESA books Eurockot Launch for Sentinel-5p Satellite. Eurockot Launch Services, January 29, 2014, accessed November 5, 2017 .
  13. ↑ Sentinel-5P News: Air-quality monitoring satellite in orbit. ESA, October 13, 2017, accessed November 5, 2017 .
  14. ↑ Mission Status. ESA, accessed November 5, 2017 .
  15. ↑ ESA: Watch live: Sentinel-5P First Light event. December 1, 2017, accessed December 2, 2017 .