In the Intelligent Perception Laboratory of Beijing University of Aeronautics and Astronautics, Zhao Huijie, a professor at the Institute of Artificial Intelligence, is immersed in the spectrum of analysis like an alien language with his students. When there is a new breakthrough in data analysis, the spectrum flashes with brighter colors than the sun, and their faces are smiling brighter than the sun.
It's like doing a CT of the Earth
For ten years, Zhao Huijie led the students to repeatedly discuss the difficult problems of hyperspectral data processing
"Looking at flowers in the fog, looking at the moon in the water, you can distinguish this unpredictable world......" The lyrics of "Seeing Flowers in the Fog" seem to describe Zhao Huijie's research process. She said, "My research area is aerospace hyperspectral remote sensing, which is to perceive the world from a macroscopic perspective. As we all know, CT examination in medicine, when the satellite distinguishes the material of the roof of various buildings from hundreds of kilometers away, and determines the mineral element content of various rocks in the field, it is equivalent to doing CT for the earth. ”
20 years ago, hyperspectral intelligent perception technology was only an imagination proposed by young teacher Zhao Huijie in a speech. In those years, the state began to vigorously develop spaceborne hyperspectral satellites to improve the management and survey capabilities of land and resources. In order to obtain high-quality hyperspectral data, it is urgent to carry out full-link modeling and full-mission analysis of satellites. However, in the face of the blockade of the mainland by foreign analysis software, there is no precedent to learn from in China, and this research is a seemingly impossible task.
After that, Zhao Huijie led the team to do a lot of research and analysis for more than 3 years, and determined the importance and urgency of research in this field, but also felt that the task was arduous and the road ahead was long, and she had been hesitant in the face of this "hard bone".
Recalling the state of mind at that time, Zhao Huijie's bright thinking and speaking speed gradually slowed down. "At a seminar on the development of young teachers in the college, Professor Zhang Weixu, a pioneer of the mainland fiber optic gyroscope business, encouraged me: Xiao Zhao, I heard that you have been studying hyperspectral recently, and you are a little afraid to do it. This direction is good, the country needs it very much, you should not be afraid, you have to be brave to try. I was 51 years old when I started making fiber optic gyroscopes, you were younger than me at that time, I believe that you will do your best, you will be able to do a good job, if you have any difficulties, you can come to me, I will do my best to support you. ”
With the encouragement of the older generation of scientists, Zhao Huijie is determined to start from scratch and build a "hyperspectral building" on the mainland. For her, who studied precision instruments, although she was doing experiments, the test objects and test environments were completely different. "My test subject has changed from an instrument to a satellite in space, and the test environment has also changed from a house to a cloud of space."
While most of the traditional spectral analysis is not imaging, hyperspectral imaging technology combines spectral resolution and pattern resolution to create a spatial dimension of area spectral analysis. For example, there are two groups of yellow in front of your eyes, one is pure yellow and the other is a mixture of red and green, which cannot be distinguished by the naked eye, but can be easily distinguished by hyperspectral imaging.
Once the door to explore the future is opened, like a twitching spinning top, Zhao Huijie's world spun rapidly. "At that time, I was young, and I was still able to stay up late." The hardships that were difficult at the beginning of everything were all the happiness of doing business in full swing in Zhao Huijie's memory.
Putting "nearsighted glasses" on the Eye of Space
The research of hyperspectral detection technology involves many fields such as payload, satellite, atmosphere, and remote sensing applications, and there are many interdisciplinary disciplines, which is very difficult to learn. With the mission of "serving the country through the sky", Zhao Huijie is not afraid of difficulties, and returns herself to the original point again and again, and goes to relevant scientific research units to re-learn professional knowledge in interdisciplinary fields.
When it comes to the self-developed hyperspectral remote sensing data application processing technology, Zhao Huijie, who has been studying day and night for 20 years, is still full of passion. In the narrow laboratory, even the space to turn around is not rich, but Zhao Huijie feels that the world is vast. I saw that the spectral lines on the computer kept jumping, and after a while, a probe image completed the data analysis. Zhao Huijie told the reporter about the "book from heaven" in front of her, just like an experienced doctor analyzing B-ultrasound images. "From this map, we can accurately analyze whether there are mineral deposits in this deep mountain forest, what kind of ore it is, and whether the compound content of the ore is more or less ......."
However, it is not easy to be subtle. Imagine yourself as a camera in space, even if you stare at one place and shoot repeatedly, there can be thousands of changes, the intensity of radiation is different, the clouds are uncertain, and a positioning can appear in a variety of forms. "This set of data analysis modeling is like putting a pair of glasses on the eyes in space to correct myopia, so that the captured images can go from blurry to clear."
With the breakthroughs made by Zhao Huijie and her team in key technologies such as high-precision surface reflectance inversion, massive data dimensionality reduction, blind decomposition of mixed pixels, and fine classification of ground objects, hyperspectral data processing and application can be detected with high accuracy, high automatism and high reliability, laying a solid foundation for the effective application of hyperspectral remote sensing in geological survey, environmental and disaster monitoring, precision agriculture, battlefield reconnaissance and other fields.
Every breakthrough has a thousand turns, and failure is inevitable. Whenever the research encounters a bottleneck, Zhao Huijie will lower her heart and return to the most basic theoretical study, constantly consolidating the foundation of the "Hyperspectral Building". "Thousands of high-rise buildings rise from the ground, every brick and tile is the foundation", Zhao Huijie said with emotion, every time she encounters a problem, she retraces the source, and finds new breakthroughs and inspiration in the process. She also shared the experience of "root-seeking" with students, "No matter how high the experiment is based on the theory, it cannot be separated from the basic theory that is rooted downward, which is the most boring and obscure part of the academics, and it is also the place that tests us the most." ”
"Early warning" for weather forecasts
After joining the newly established Institute of Artificial Intelligence in 2020, Zhao Huijie began to actively learn the knowledge of artificial intelligence and tried to carry out interdisciplinary research. During the survey, she was surprised to find that the application of artificial intelligence technology to accurate weather forecasting is a research hotspot in the field of artificial intelligence.
In May 2022, the "Notice of the State Council on Printing and Distributing the Outline for High-quality Development of Meteorology (2022-2035)" was released, and the key goal mentioned that the key core technologies of meteorology should be independent and controllable as soon as possible. United States meteorology was the first to develop, and many technologies were highly monopolized, especially hyperspectral meteorological satellite detection technology. To this end, Zhao Huijie and her team also ushered in a new topic, this time they want to break through the technical blockade and realize the improvement of the mainland's meteorological monitoring precision, accurate forecasting, and fine service capabilities.
Timely and accurate weather forecasts and early warnings can help people be prepared for drastic and unpredictable weather changes, reduce property losses caused by natural disasters, and protect people's lives. "For example, the current weather forecast can predict whether it will be heavy rain or light rain a few hours in advance, and hyperspectral meteorological satellites can make the forecast more 'timely', more time in advance and with a more accurate time and location to predict ......," Zhao Huijie explained, perhaps ordinary people do not need to be too accurate to predict, but in fact, industries that are strongly related to the weather, such as aviation, shipping, logistics, new energy vehicles (autonomous driving), etc., are in urgent need of more and more accurate meteorological information.
It's just that the weather is the most elusive. Different from previous radar monitoring technology, hyperspectral monitoring can interact with temperature and humidity in the atmosphere, and by observing spectral changes before the formation of radar-detectable water droplets, it can predict a storm that has not yet brewed, "This is the magic of hyperspectral".
Even if she is gnawing on the hardest "bones", Zhao Huijie is like a child who is about to run to the playground, and she can't hide her joy and expectation. This love for science began as early as her childhood. When Zhao Huijie was in middle school, her physics teacher asked her classmates to prove their conclusions using different test methods than those in the books. "At that time, I was the only one who answered it, and although it was not perfect, the teacher gave me a perfect score. It is this encouragement that makes me always full of confidence, and I firmly believe that I can no matter how difficult the subject is. ”
In 2024, with the rapid development of artificial intelligence, many studies will be subverted and replaced. In the face of this wave, Zhao Huijie was calm. "We are the front-end of artificial intelligence, and we are the data providers that make artificial intelligence smart." In fact, a few years ago, Zhao Huijie began the research of intelligent perception technology, and now she is leading the team to continue to learn artificial intelligence theories and methods, and strive to make new contributions in the field of intelligent perception of complex environments.
From the determination to lead the team to carry out the research of hyperspectral detection technology, to the launch of a series of scientific research and experimental satellites, and then to the commercial hyperspectral satellite put into use...... The scientific research achievements of Zhao Huijie's team have been recognized by peers at home and abroad.
Looking back on the way she came, she was full of emotion: "I would like to sincerely thank the leaders and experts who have given me strong support and help in every time I overcome difficulties. I want to pass on this spirit from generation to generation and carry it forward. ”