China News Network: Interpretation of China's carbon satellite how to "see small"

      December 22 morning in Jiuquan Satellite Launch Center successfully launched the Chinese carbon satellite, can be summarized as "small see big."

      First of all, "small" body has "big" skills.

      The carbon satellite weighs about 620 kilograms and consists of three parts: a modular satellite platform, a hyperspectral and a high spatial resolution carbon dioxide detector, a multi-spectral cloud and aerosol detector.

      To meet the carbon satellite in five kinds of observation mode and more than ten kinds of pointing mode to switch between the requirements, satellite platform researchers to create a good "body". Chinese Academy of Sciences Institute of Microsatellite Innovation Institute of carbon satellite chief designer Yin Zengshan said, "complex attitude pointing control system" so that the satellite can be a large angle gesture maneuvers, jump out of "space waltz".

      Hyperspectral and high spatial resolution carbon dioxide detector, with a resolution of 0.04 nm to refresh the new record of Chinese spectroscopy. Zheng Yuquan, a researcher at the Changchun Institute of the Chinese Academy of Sciences, said that the first time, the establishment of holographic diffraction grating manufacturing system and related testing, the equivalent of forging a filter color "comb."

      The working principle of the detector is in the visible and near infrared spectral section, the use of molecular absorption lines to detect carbon dioxide concentration. Zheng Yuquan explained that the carbon dioxide molecules in the air will have different degrees of absorption of sunlight, the detector first accurate measurement of "color", and then reverse the number of carbon dioxide molecules.

      Multi-spectral cloud and aerosol detector is responsible for measuring cloud, atmospheric particles and other auxiliary information for the scientists to reverse the deduction of carbon dioxide concentration interference factors. Yang Zhongdong, chief architect of carbon satellite engineering ground application system, said that this instrument is not a "protagonist", but it can monitor the particles in the atmosphere, will study PM2.5 and other atmospheric pollution causes important data support.

      Second, the "big" noise to find "small" target.

      Yang Zhongdong said that the absolute content of carbon dioxide gas, in the big "noise" to find a small number of targets, very difficult. "The advantages of the unit together to focus on joint research, to fill the gaps in domestic technology."

      Such as multi-spectral cloud and aerosol detectors. Carbon dioxide and aerosols are similar, through this instrument, both to solve the carbon dioxide monitoring of the "noise" interference problem, but also help to scientifically analyze the link between the two.

      According to the design requirements, carbon dioxide concentration monitoring accuracy of carbon satellites is better than 4ppm (parts per million). In the atmosphere, the concentration of carbon dioxide is only four ten thousandths. In other words, carbon satellites can detect a 1% change in the concentration of carbon dioxide.

      According to reports, carbon satellite began to work for up to 3 years, the daily record of about 10 hours of data. When it was busy in the sky, Jiamusi, Urumqi and the Swedish base station composed of carbon satellite receiving station network is responsible for receiving processing data.
Finally, the "small" satellite bear the "big" mission.

      China's Ministry of Science and Technology National Remote Sensing Center chief engineer Li Jiahong said that in a variety of greenhouse gases, carbon dioxide and human activities and even each country's economic base is closely related, and thus a unique position.

      There have been two carbon dioxide monitoring satellites in the world: Japan's "breathing" greenhouse gas observation satellite launched in 2009, the OCO-2 satellite launched by the United States in 2014.

      Li Jiahong said that carbon satellite not only filled the gap in China in the field, and the overall level is higher than the "breathing" number. It dynamically monitors the concentration of carbon dioxide in the global atmosphere, giving global carbon distribution data not only reflects China's response to global climate change, but also demonstrates the responsibility of responsible countries.

      After the on-orbit test, the carbon satellite will undergo a "physical examination" of the earth every 16 days, and after 2-3 months the data has been accumulated to complete the full coverage of the earth. Scientists can get from different seasons, different areas of carbon emissions "physical examination report."

      It is understood that the official has developed a carbon satellite data management approach, will be timely and shared data at home and abroad. Carbon satellite data has also been loaded into the national integrated Earth observation data sharing platform and is included in the annual report on the annual eco-environmental monitoring of remote sensing.

      Li Jiahong said China will also share carbon satellite data with Earth observation organizations and carry out in-depth research through the "Long Plan" of China and Europe. Scientists hope to form a joint observation with Europe and the United States and other carbon satellites, the common benefit of mankind.

      Source: Changchun light machine