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China’s Strategic Earth Observation Satellites; By Vithiyapathy Purushothaman (李拯)

Image Courtesy: The Asian Age

Article No. 041/2019

On October 5, 2019, as a part of the High-definition Earth Observation project, the 314th flight mission of Long March has successfully placed Gao Fen-10 in its planned orbit. Previously, Gao Fen-10 was launched on 31 August 2016 on a CZ-4C rocket from China’s Taiyuan space center but it didn’t succeed to orbit. Thus, it was relaunched after three years from the same space center.

In 2010, the Chinese government initiated the High-Definition Earth Observation Satellite (HDEOS) program. The main objective of the program is to utilize sufficient Near-Real-Time (NRT) observation data for city planning, intelligent transportation, geographical mapping, resource surveillance, precision agriculture, disaster management, environment surveying, and climate change monitoring. Later, to improve the comprehensive capability of its Earth observation system, the HDEOS project has extended to CHEOS (China’s High-Resolution Earth Observation System). EOSDC-CNSA (Earth Observation System and Data Center – China National Space Administration) monitors the construction and maintenance of the CHEOS program. China Aerospace Science and Technology Corporation (CASC) is the prime contractor for building space segments of CHEOS and ground segment is operated by the Centre for Resources Satellite Data and Application (CRESDA). The project focused to build the meteorological, marine, resource, environmental and, high definition satellites. Thus, it successfully inducted GaoFen – High Definition Earth Observation Satellites, Feng Yun – weather satellites, Hai Yang- Ocean observation satellites, Zi Yuan -resource Satellites, Yaogan – remote sensing satellites and Tian Hui – Topographic Mapping -Satellite in its planned orbit. Thus, on completion of CHEOS program, it can meet the strategic demands of the national economic development and social progress as well as it will have a clearer view of the planet.

Gao Fen – High-Definition Earth Observation Satellites

Gao Fen satellite series are placed in a sun-synchronous orbit (SSO) except Gao Fen -4 geostationary satellite. Its data can be applied in monitoring natural and agricultural resources, surveys of forest and wetland resources, estimating crop yields, pollution monitoring, and disaster alerts.

The details of the Gao Fen satellite series are as follows:

Gao Fen -1 series is a constellation of four satellites and it can cover the globe in four days.  GF-1-01 is an optical satellite was launched on 06 Apr 2013 and GF-1-02, 03 and 04 were launched together on 31 Mar 2015. The three satellites are equipped with a 2m resolution pan-chromatic camera, 8m resolution multi-spectral camera and 16m resolution wide-angle multi-spectral camera.

Gao Fen -2 was launched on 19 Aug 2014. It can collect multispectral images of objects greater than 3.2 meters in length with accuracy up to 0.8 m in full color. It is said to be the most advanced earth observation satellites likely to have a superior resolution. Gaofen-2 is capable to see 1 m long objects from space in full color.

Gao Fen – 3 was launched on 09 Aug 2016. It is a multi-polarized high-resolution synthetic aperture radar (SAR) imaging satellite. It was China’s first SAR satellite which is capable of providing 24-hours global observation service used for disaster warning, weather forecasting, land and water resource assessment as well as used for the protection of maritime rights. It provides data to the State Oceanic Administration (SOA), Meteorological Administration and benefits Ministry of Civil Affairs and the Ministry of Water Resources.

Gao Fen- 4 was launched on 28 Dec 2015. It is the geosynchronous orbit high-resolution optical imaging satellite that is used for emergency monitoring of Typhoon and to provide data assistance during disaster alert, rescue and assessment. It is equipped with a 50m camera, visible light infrared cameras. Its focus covers up to 4,350 miles in an individual scene with a capacity of high temporal resolution remote sensing monitoring capability at a minute level. It has an ability to see an oil tanker and can produce the best image than any other high-orbit remote sensing satellites in the world.

Gao Fen -5 was launched on 08 May 2018. It is China’s first hyperspectral imaging satellite. It carries six state-of-art observation instruments such as advanced hyperspectral imager, visual and IR Multispectral Sensor, Greenhouse gas monitoring instrument, atmospheric infrared ultra spectral sensor, environment monitoring instrument and the directional polarization camera. It is designed to detect variations in global land and water resources, tracking air pollution and greenhouse gases in the atmosphere.

Gao Fen-6 was launched on 02 June 2018. It is similar to the operations of GF-1. It is utilizing various instruments consisting of a 2/8 resolution hyperspectral camera and a 16m resolution wide-angle camera. Both cameras use a three-mirror anastigmatic telescope to covers visible light to NIR bands where its wavelength ranges from 450nm to 900nm. It supports both Chinese province planning by supporting more than 20 fields as well as it produces data for China’s International space cooperation through Space and information programs of BRI.

Gao Fen-8 was launched on 26 June 2015.  is an optical high-resolution imaging satellite. It lacks public source information about its equipment, yet it is said to be a civilian model of Yaogan 26 military reconnaissance satellite.

Gao Fen-9 was launched on 14 Sep 2015. It is a civilian version of Yaogan 2 type military reconnaissance optical remote sensing satellite that is capable of providing photographs with a resolution of less than a meter. It is China’s first agile earth-Observation satellite with three-dimensional freedom.

Gao Fen-10 failed to orbit on 31 Aug 2016 and successfully relaunched on 05 Oct 2019. On the series, GF-10 is said to be equipped with remote sensing SAR to provide High-definition Earth observation images. Yet the purpose and equipment loaded in GF-10 are not briefed in public domains.

Gao Fen-11was launched on 31 July 2018. It is a sub-meter optical remote sensing satellite. As a part of Gao Fen series, it can provide all-day, all-weather coverage with optical and Synthetic aperture radar.

Feng Yun – Weather Satellites

Feng Yun is a weather satellite series. Feng Yun literally means ‘Wind Cloud’. FY-1 and FY-3 series are polar-orbiting sun-synchronous satellites whereas FY-2 and FY-4 are geosynchronous satellite series. Notably, FY-1C was destroyed during the anti-satellite missile test. These meteorological satellite series are focused on navigation, aviation, forestry, agriculture, oceanography, environmental protection and needless to say its role in national defense. It provides data to the Meteorological Administration of China (CMA).

Hai Yang- Ocean Monitoring Satellite

Hai Yang literally means ‘Ocean’. Hai Yang is an Ocean monitoring System with remote sensing capability. It functions under the National Satellite Ocean Application Service (NSOAS) and provides data for State Oceanic Administration. HY-1 satellite series is a Coastal Zone Imager (CZI) as well as Chinese Ocean Color and Temperature Scanner (COCTS). HY-2 series satellites contain a Microwave radiometer imager, a Radar altimeter and Scatterometer (Ku-RDSCAT). The data obtained are used to survey aquaculture resources and to monitor islands, and coastal zones, marine disaster relief and sustainable utilization of ocean resources.

Zi yuan – Resource Satellites

Zi Yuan is an earth resource satellite program. The ZY-1 is equipped with a three-dimensional survey camera, multi-spectral, and CCD (Charge-coupled device) cameras. The survey cameras are capable of producing 5 meters accuracy images and the multi-spectral camera could capture 60 km images with a ground resolution of 10m. It is jointly operated by Brazil institute of space research and China ‘s Center for Earth Operation and Digital Earth (CEODE). It is also known as China-Brazil Earth Resources Satellites (CBERS). The ZY-2 program is reportedly used for aerial surveillance and is operated by the People’s Liberation Army (PLA). The ZY-3 series are equipped with cameras. Its sweep area width is 52 km. It is used for stereo mapping and is operated by the State Bureau of Surveying and Mapping. There have also been indications that the development of the Tianhui-1 program was merged with the Ziyuan-3 project planned for launch in 2011.

Tian Hui – Topographic Mapping Satellites

Tian Hui is a satellite series for the evaluation of ground resources and mapping. It is equipped with visible and infrared cameras to produce three-dimensional pictures.

Gao Jing (Super View) Satellites

Super view series minisatellite’s maximum single scene can be 60 km x 70 km of video data. It is a sun-synchronous satellite and it can perform multiple image collection including stereo imaging, collect long and multiple strips as well as multiple point targets image collection. The major objective of the Super View satellites is to provide imagery with 0.5m panchromatic resolution and 2m multispectral resolution on a swath of 12km.

Strategic advantages

China had successfully developed its Gao Fen, Feng Yun, Hai Yang, Zi Yuan and Tian Hui satellite series for attaining supremacy in earth observation. These satellites have made great contributions in city planning, weather forecasting, climate variation and ocean monitoring, environment and disaster monitoring and forecasting. Therefore, CHEOS reduces China’s dependence on foreign remote sensing satellites. CHEOS program was determined to focus on the elements of the ground system, aerial system, spaceborne system, the near-space system and application system in order to attain earth observation at high temporal, spatial and spectral resolution. Notably, on the other side, China began its BeiDou’s preliminary global services for sharing its positioning data to its customers and to expand China-based applications which are used worldwide. Chinese arms sale is expanding in Asian and African landscape. As per the SIPRI 2019 report, Chinese arms industries export weapons to 53 countries. CHEOS strategic satellites have an adverse effect on the expansion of China’s military strength as well as improved its effective space diplomacy among its BRI member nation. As per the Global Times states that these observation satellites can also serve as a key national strategy such as the Belt and Road Initiative. On the successful launch of Gaofen-7 in November 2019, China will achieve its global earth observation supremacy through its Gaofen satellite constellation. China also shares the Gao Fen data with its countries that cooperate with the Belt and Road project by providing an accurate high definition image for supporting the city government of the nations.

Satellite Surveying and Mapping Application Center (SASMAC) of China’s National Administration of Surveying Mapping and Geo-information (NASG) is intended towards improving global and regional cooperation on Earth Observation for public benefits. Within the framework of the Group of Earth Observation (GEO), SASMAC is further gaining experience with international Charter ‘Space and Major Disasters’. It chaired the CHARTER in 2014 by taking the role of Emergency On-Call Officer (ECO). China expanded its bilateral space cooperation based on observation satellite data. Earth observation cooperation is focused on Russia, the European Space Agency (ESA), Brazil, and France. Further, China engages in multilateral cooperation with the UN for Earth Observation data sharing, technical support and cooperation. Beyond supports and cooperation, China encourages commercial launches of communication and remote sensing satellites. It exports the satellites of Nigeria, Bolivia, Laos, Belarus, and earth observation satellite of Turkey and supports to launch small satellites of Ecuador, Argentina, Poland, Luxemburg. China is excelling in the global information technology infrastructure. Therefore, it is heading towards the successful completion of the BRI Space information corridor by 2020.


References:

  1. Xinming Tang. China’s SASMAC advances regional cooperation on Earth observations. Group on Earth Observations. October 18, 2017. http://www.earthobservations.org/geo_blog_obs.php?id=254

  2. GF-2 (Gaofen-2) High-resolution Imaging Satellite / CHEOS series of China. eoPortal Directory. https://directory.eoportal.org/web/eoportal/satellite-missions/g/gaofen-2

  3. China Aerospace Science and Technology Corporation. http://english.spacechina.com/n16421/index.html

  4. Li Xia. Two Chinese Earth Observation satellites put into service. Xinhua net. March 3, 2019. http://www.xinhuanet.com/english/2019-03/21/c_137913427.htm

  5. Wang, S., Yang, B., Zhou, Y., Wang, F., Zhang, R., & Zhao, Q. (2018). Three-dimensional information extraction from GaoFen-1 satellite images for landslide monitoring. Geomorphology 309, 77-85.

  6. Zhang, G., & Guan, Z. (2018). High-frequency attitude jitter correction for the Gaofen-9 satellite. The Photogrammetric Record, 33(162), 264–282.

  7. Gu, X., Song, B., Wang, J., & Zhou, X. (2009). Earth observations and their applications in China. Earth Observing Systems XIV.


(Mr. Vithiyapathy Purushothaman, Ph.D. scholar, School of Humanities and Social Science, University of Science and Technology of China (USTC), Hefei, PRC, Former Research Officer, C3S; and Associate Member, C3S.)

(The views expressed are the author’s own)

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