Sifuqi: Seeing the blue sky to see the future

In the atmosphere within 120 kilometers from the Earth's surface, in addition to nitrogen, oxygen and noble gases, there are many trace gases, these trace gases, although the volume concentration is small (less than one ten-thousandth of a percent), but its changes will have a significant impact on the Earth's atmosphere and ecological environment, such as the familiar greenhouse effect, the ozone hole and so on.

At this stage, the haze process in some areas of China is inseparably related to trace gases, such as nitrogen oxides, ozone, and volatile organic compounds. To thoroughly study and solve the problems of air pollution and global climate change that are closely related to us, we need to measure the concentration and emission flux of trace gases in the atmosphere more accurately, and Sifqi is working hard to do so.

Before the 2008 Beijing Olympics, although China set up city-centered automatic air quality monitoring stations to monitor sulfur dioxide (SO2), nitrogen dioxide (NO2), and respirable particulate matter (PM10) in the air on a daily basis, the monitoring data did not fully reflect the true state of air pollution, and the results of the air quality evaluation were not consistent with the public's intuition. The results were inconsistent with the public's intuition. At that time, the monitoring of near-Earth air pollution could not meet the needs of research on the formation mechanism, evolution and transmission process of air pollution, and lacked regional and three-dimensional monitoring technology methods.

Soon, a high-tech team located in Hefei, Chinese Academy of Sciences, Anhui Institute of Optical Machinery, stood out, in the national research program support, they developed a solar scattered light based on the ground-based atmospheric trace gas column concentration and its profile online monitoring system - multi-axis differential absorption spectrometer (MAX-DOAS), to achieve the atmospheric trace gas column concentration and its profile online monitoring system (MAX-DOAS), to achieve the atmospheric trace gas column concentration and its profile online monitoring system (MAX-DOAS). , realizing the real-time detection of atmospheric trace pollution gas column concentration and its vertical distribution, which is of great significance to the study of regional atmospheric pollution spatial and temporal distribution and propagation law, and provides data support for the mechanism of atmospheric pollution formation and the dynamic evolution process of pollutants.

"We have carried out outside air quality monitoring at large-scale events in recent years, such as the 2008 Beijing Olympics, the 2010 Shanghai World Expo, the Guangzhou Asian Games, the 2014 Youth Olympic Games, and the APEC meeting in Beijing, and have assessed the effectiveness of environmental air quality protection measures for major national events with scientific data. " Si Fuqi said, "Among the various means of measuring pollution, optical remote sensing is one of the more representative methods, which can measure a wide range, fast, multi-component and non-contact." Sifuqi team to obtain the relevant data adopted by the environmental protection department, not only become the relevant basis for them to develop policies, or their assessment of the effectiveness of the implementation of the policy, has a significant role.

In addition to escorting major national activities, the Multi-Axis Differential Absorption Spectrometer (MADAS) has been involved in several polar scientific expeditions since 2010, and has carried out long-term observations at the Yellow River Station in the Arctic and the Great Wall Station in the Antarctic to monitor ozone and halogen oxides in the polar region. As a long-term deployed equipment in polar stations, the Multi-axial Differential Absorption Spectrometer accurately measured the trend of the total ozone column over the poles, providing technical support for China's polar scientific research. The technology won the first prize of the Environmental Protection Science and Technology Award in 2011.

"We are doing monitoring, we need to get first-hand raw data, and designing and developing monitoring equipment is our most important work." To this end, Sifuqi's team is not only responsible for independent research and development of experimental equipment to monitor changes in the atmospheric environment, but also docked with domestic environmental protection enterprises, so that the instrument on the ground production. They developed the imaging differential absorption spectroscopy technology, innovative and successful airborne imaging differential absorption spectrometer for rapid measurement of regional pollutant gases. They cooperated with the company to industrialize the technology, and have now promoted a number of sets of airborne imaging differential absorption spectrometer, successfully obtained high-resolution regional pollution gas two-dimensional distribution information, filling the gaps in the domestic relevant data.

During his work, Mr. Sifuqi went to the University of Heidelberg in Germany for a period of study and exchange. Germany is a pioneer in trace gas observation, in terms of equipment, instruments, experimental methods and experience, Germany is ahead of China. Today's Anhui Institute of Optical Machinery of the Chinese Academy of Sciences has developed a series of high sensitivity, high stability of environmental monitoring technology and equipment for China's national conditions, for China's effective assessment of air pollution, fine traceability and prevention and control to provide key technical support. Now China and foreign countries have been basically on the same level, generations of researchers have paid countless efforts for this, he lamented.

On May 9, 2018, the "Gaofen V" satellite was successfully launched from Taiyuan Satellite Launch Center. This is China's first domestic satellite that can effectively detect atmospheric pollution gases. With it, China will grasp global air pollution data from a satellite platform for the first time. Si Fuqi as "Gaofen five" satellite atmospheric trace gas differential absorption spectrometer load of the chief designer, excited, he for this day, has been struggling for eight years.

Rewind to 2010, in that year, an extremely important thing happened, high-resolution earth observation system major special (hereinafter referred to as "high score special") was approved to start the implementation of this is the "national medium and long term scientific and technological development planning program (2006-2020)," the 16 identified by the national scientific and technological development plan (2006-2020), and the "high score special" is the first time to start the implementation of the program. This is one of the 16 major scientific and technological specialties identified in the "Outline of the National Medium- and Long-Term Science and Technology Development Plan (2006-2020)". In order to fill the gaps in China's high spectral resolution earth observation, the Gaofen Special Project explicitly proposes a multi-sectoral linkage to form a national infrastructure platform, and includes the Gaofen series of satellites in the sequence of scientific research satellites. Si Fuqi's Key Laboratory of Environmental Optics was selected by the state to participate in the scientific research of the Gaofen series of satellites because of its good accumulation of ground-based and airborne equipment and related algorithms.

"We started doing it in 2010, and it took us eight years to make a satellite payload, the Atmospheric Trace Gas Differential Absorption Spectrometer (EMI for short)." Regarding satellite equipment, Sifuqi hasn't done it, he's only done ground equipment and airborne equipment, which is a big difference. Satellite equipment emphasizes reliability, non-maintainable, non-repairable, must be a success, the engineering requirements are very high, which is a brand new challenge for Sifuqi, but also extremely important, must be accomplished.

In Europe, the first satellite that can measure atmospheric pollution gases was successfully launched in 1995, and since then Europe has been able to observe the global air pollution situation using satellite data. In 2018, China successfully launched the "Gaofen-5" satellite, a difference of 23 years. Especially in the previous international negotiations, China has been criticized for not having its own observation data and not being able to grasp the right to speak.

But with EMI, everything is different. A month after the successful launch of the "Gaofen 5" satellite, the relevant personnel according to its return data, mapping out the global pollution situation, the Chinese people finally have their own global air pollution observation system. And Si Fuqi hanging heart can finally put down. "Before the map was sent back has been very nervous, because you do not know how the launch up will be, although a variety of ground tests we have passed, but we are, after all, the first time to do it, a lot of things are unknown, the pressure is still very big."

Today, Si Fuqi recalls this process from scratch, still feel very difficult. "Because the first time I did it, there are more problems, press down the gourd to start the ladybird, a bit of a handful." But just because of the constant problems, he is also moving forward, constantly finding problems and solving them. Sifuqi and the team not only did the hardware equipment, but also took on the late data processing software development work, developed 0 1 level data processing business processing software, deployed in China Resources Satellite Application Center, realizing the real-time batch production of level 1 products, and quickly distributed to environmental protection, meteorology and other industry users. On this basis, they produced a map of global nitrogen dioxide distribution. "According to the jargon, this is the first global distribution map of nitrogen dioxide with domestic self-developed equipment." Sifuqi said confidently.

EMI load is still China's highest spectral resolution in the ultraviolet and visible bands of the load, but also China's first atmospheric pollution gas observation load. After this battle, Anhui Institute of Optical Machinery of the Chinese Academy of Sciences officially became one of the members of the "space club".

The EMI payload has been launched to initially meet the needs of the Ministry of Ecology and Environment and other departments of atmospheric pollution data, changing the situation of such products are subject to foreign countries. However, Sifuqi is not satisfied with this, he knows that there are still differences with foreign loads and the further needs of the user, there is an urgent need to research and development of atmospheric environment monitoring special satellite payloads, enhance the spatial resolution of the data products, temporal resolution, and to achieve the volatile organic compounds, tropospheric ozone and other atmospheric components of the measurements, to provide accurate satellite data products for the user, to cultivate the environment of the optical remote sensing instruments, satellite data products applications and other strategic emerging industries to provide the best possible results. It will provide technical support for the cultivation of environmental optical remote sensing instruments, satellite data product applications and other strategic emerging industries. In this "blue sky defense war", they will not be absent.

Now, Sifuqi's team has more than 20 fixed employees, more than 20 doctoral and master's degree students, and young and middle-aged scientific and technological personnel under the age of 45 accounted for 90% of the total number of professional and technical personnel, specializing in the fields of atmospheric physics, environmental sciences, optics, electronics, precision instruments and other fields.

Over the past five years, the laboratory has added more than 35 million yuan of fixed assets, including vacuum high and low temperature simulation test system, deep ultraviolet spectral/radiation calibration system and other equipment, but also has a laboratory area of more than 2,000 square meters, including nearly 500 square meters of 10,000 optical clean room, 50 square meters of 1,000 optical clean room, 200 square meters of anti-static electronics electrical installation, assembly and adjustment laboratories. etc.

A good team is even more so that scientific research can not stop. "On the basis of the EMI load, we made an EMI-II load, the spatial resolution from the previous 48 kilometers to 24 kilometers, doubled, the load carried in the 'Gaofen five' 02 star, atmospheric environment monitoring satellite and other three satellites, is expected to launch two this year. " In addition, the team also made a high-precision atmospheric pollution gas monitoring payload, its spatial resolution can reach 7 kilometers 7 kilometers, at the same time, the payload has a proximity observation function, able to provide a vertical resolution of 1 kilometer pollution gas contour results for the Ministry of Ecology and the Environment and other users of high-quality satellite data, to promote the development of China's environmental monitoring optical remote sensing instrumentation industry. It is also the most advanced level in the international arena and is expected to be launched in 2023.

In order to be able to complete the lead, Si Fuqi always keep a close eye on the latest foreign technology. "Now the international development of high orbit technology, relative to the low orbit payload, high orbit payload has a higher time resolution, at present the world's first high-orbit atmospheric pollution gas monitoring satellite is sent by South Korea, called GEMS, but its data has not been completely open, or some clichéd content, said that the atmospheric pollution is over the China, China's influence on South Korea is very large, and so on. " So attack the high orbit platform effective atmospheric remote sensing payload development problems, the realization of the global and regional distribution of pollution gases, vertical contours of the high spatial and temporal resolution, high precision remote sensing monitoring is Si Fuqi's team in the next five years of the focus of the plan. "During the '14th Five-Year Plan' period, if we can do a good job on one or two of them, so that China can have the right to speak and accurately identify the sources of pollution, it will be our team's success and contribution to the country." This is Si Fuqi's expectation, but also the expectations of generations of researchers.

Fuqi Si, a researcher and doctoral supervisor at the Hefei Institute of Physical Sciences of the Chinese Academy of Sciences (HIPCS), is mainly engaged in research on optical information processing, optical and spectroscopic monitoring methods for trace gases, etc. He received his doctoral degree in optics from the Anhui Institute of Optical Machinery of the Chinese Academy of Sciences (AIOMET) in 2006, and has carried out research at the University of Chiba in Japan, and at the University of Heidelberg in Germany.

For more than 10 years, he has been engaged in the research of optical remote sensing monitoring technology, and has passed the appraisal of many scientific research achievements, and has been authorized 27 invention patents, and published more than 140 papers. He has been awarded the second prize of National Science and Technology Progress, the first prize of National Environmental Protection Science and Technology Award, the first prize of Anhui Provincial Science and Technology Award, and the Excellent Youth Fund of Anhui Province.

As the chief designer of China's first satellite-based atmospheric trace gas monitoring payload, he was responsible for the development and in-orbit operation of the payload, and successfully obtained the first global distribution map of atmospheric pollutant gases such as nitrogen dioxide and other air pollution gases from a domestic satellite, which changed the status quo that the data of the distribution of atmospheric pollutant gases on satellite were restricted by foreign countries. At present, the focus of the development direction for the ultraviolet, visible band trace gas measurement technology research and the realization and application of the above technology in the ground-based, space-based, star-carrying platform, ultraviolet radiation measurement research.