Members of the greenhouse gas load team of the Shanghai Institute of Technology and Physics, Chinese Academy of Sciences, are conducting a vacuum light calibration test using an integrating sphere to simulate sunlight.
This Spring Festival, the space-based carbon monitoring commando team of the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences has been sticking to the laboratory. According to the scientific research task arrangement, the hyperspectral greenhouse gas detector developed by the team is about to be accepted in stages, and they have to seize the window period to carry out the final calibration and calibration of the instrument.
In this team of more than 20 people, there are both post-60s and post-00s, and the largest number is post-90s, whose hometowns are far away in Gansu, Sichuan and other places. What is touching is that the project team did not notify everyone to work overtime during the Spring Festival, but everyone stayed very tacitly. Yang Yi, project leader of the hyperspectral greenhouse gas detector, said: "It is very fortunate to overcome difficulties and chase dreams with a group of like-minded friends. Huang Sunan, the chief designer of machinery, said: "I feel very happy to do what others have not done, and my family is very supportive." ”
Jackie Chan, the deputy chief designer of optics, has been aiming in this direction for 9 years since he started studying for his doctorate. He said: "The greatest luck for scientific researchers is to participate in cutting-edge projects that the country needs, and now that the project is nearing completion, I want to do it better." ”
There are "three difficulties" for new loads to take the lead in exploring the way
To achieve "carbon peak" by 2030, you need to know the data of global greenhouse gases - who emits them? How much is lined up? They're gone again**? As soon as the Copenhagen climate conference ended in 2009, China began to deploy the development of carbon satellites, and the first carbon satellite to monitor global carbon dioxide concentrations was successfully launched in 2016. However, in addition to carbon dioxide, greenhouse gases also include water vapor, methane, nitrous oxide, etc., and in order to have a more accurate grasp of carbon emission data, it is necessary to "see more".
At present, all greenhouse gas monitoring in the world only "looks" at carbon dioxide as a gas, and "more" means that this is a road that no one has traveled before. Around 2008, the Shanghai Institute of Technology and Physics, Chinese Academy of Sciences, took the lead in carrying out advance research on space-based greenhouse gas monitoring technology.
There are three difficulties in taking the lead in exploring the way. Ding Lei, director of the Shanghai Institute of Technical Physics and chief designer of the instrument, explained: "First, the spectrum needs to be wider and more precise in order to observe the concentration of more gases in space and 'see' the details;Second, the field of view must be larger, the field of view width of similar instruments is generally more than 10 kilometers, and the instruments we developed need to cover 100 kilometers in order to effectively shorten the detection period of the world and sensitive areas; Third, information processing is more difficult, which poses new challenges to device accuracy, ground testing, and instrument research and development. ”
To this end, Shanghai Institute of Technology and Physics has joined forces with the strongest scientific research forces of all parties in the country to tackle key problems, and has completed the development of the world's first wide-range high-precision greenhouse gas detector prototype. Compared with the current international similar loads, its total optical field of view has increased by 7About 3 times, the spectral resolution is doubled, the spectral sampling rate is increased by 50%, and the signal-to-noise ratio is increased by 30%, which can achieve high-precision detection of methane, and is expected to improve the greenhouse gas inversion accuracy to 1ppm (parts per million).
Precise "tuning" in a simulated space environment
On the eve of the Spring Festival, the hyperspectral greenhouse gas detector was sent to the -120 cryogenic vacuum chamber, where it will experience the tests that must be put through the simulated space environment for the next half month.
Just as an instrument needs to be tuned before it can be played, the mathematical quantities of the spectrum are converted into the actual physical quantities of the gases in the atmosphere, and calibration also needs to be calibrated. As a brand-new self-developed payload with leading indicators, the engineering volume of this link is huge.
Zhang Dongdong, chief designer of integrated electronics, said: "We used more than 4,000 spectra, and it takes 24 hours of uninterrupted debugging to make them highly sensitive feedback data indicators in harsh environments and consistent with actual observations." ”
In the initial plan submitted by Lei Songtao, deputy chief designer of machinery, the weight of the instrument reached 600 kilograms, and the revised opinions required that the weight be reduced to 300 kilograms. In order to achieve this, almost all materials and structures in this load have been completely redesigned, which will also be tested in low-temperature vacuum tests. "Under different temperature and gravity field changes, our load deformation cannot exceed the micron level. Lei Songtao said.
If all goes well, in March this year, this hyperspectral greenhouse gas monitor will usher in a phased acceptance. In the future, it will be installed on a carbon satellite developed by Shanghai to detect the concentration of greenhouse gases in the global atmosphere from space, providing data reference for the realization of "carbon peak".
Author: Shen Yusha.
Text: Reporter Shen Shatu: Yuan Jing Editor: Fu Lu.
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