Profile: Li Deren, trailblazer of China's remote sensing technology

BEIJING, June 25 (Xinhua) -- Chinese photogrammetry and remote sensing expert Li Deren, one of the two laureates for the country's top sci-tech award for the year 2023 unveiled on Monday, has devoted his life to advancing China's capabilities in surveying and remote sensing for Earth observation.

Born in 1939 in east China's Jiangsu Province, Li later enrolled at a Wuhan-based college in 1957, majoring in photogrammetry and remote sensing.

Recognizing China's urgent need for surveying and mapping technology, Li aligned his personal goals with the country's development goals and pursued further studies abroad in Germany in 1982.

During his stay in Germany, Li worked more than ten hours daily, taking two years to complete studies that would typically take five to six years.

He introduced the iteration method with variable weights, also called "Li Deren Method", to deal with systematic errors, which garnered significant attention in the academic community.

Upon earning his doctorate by the end of February 1985, Li promptly returned to China, declining multiple job offers from foreign research institutions but joined his alma mater in early March.

"No matter how good my personal life might be, without a strong nation, I would still face disrespect," Li said.

UNFORGETTABLE REGRET

A catastrophic earthquake struck Wenchuan County in southwest China's Sichuan Province in May 2008, exposing the country's inadequate satellite infrastructure for rapid post-disaster information acquisition.

Li, upset about the delay in satellite data, blamed himself for his incompetence in speeding up his research in remote sensing.

Determined to rectify this, Li intensified efforts to bolster China's satellite network, leading to significant advancements in Earth observation capabilities over the past decade.

His team's efforts have significantly advanced China's satellite imaging capabilities for civilian applications, achieving a resolution of 0.5 meters and reducing the processing time for remote sensing data from hours to mere eight minutes. These advancements have positioned China as a global leader in this field.

During the 2023 flood season, Li's team utilized the "Luojia-2" satellite to identify a breached dike in Hebei Province, enabling timely evacuation and saving over 6,400 lives.

Li said on China's Space Day in April this year that the country's satellite remote sensing technology capabilities has come a long way from its nascent stages to a position of excellence. It has now reached a mature level featuring self-reliance, security, and reliability.

"China's remote sensing services will not only fulfill domestic needs but also serve the global community," he added.

GREATEST JOY

When Li came back to China after finishing overseas study, the country's photogrammetry and remote sensing sector faced foundational challenges and a shortage of talent. Li tackled these issues starting with the compilation of teaching materials for higher education.

"Teaching brings me the greatest joy in life, and nurturing talents from one generation to the next brings our country new hope," noted Li.

Despite his numerous achievements, Li has kept delivering regular lectures to college freshmen with classrooms consistently filled.

He always encourages his students to think critically and face challenges with courage. He has so far mentored over 100 PhD graduates, many of whom are making significant impacts in the fields of photogrammetry and remote sensing and beyond.

Gong Jianya, a former student of Li's and an academician of the Chinese Academy of Sciences, has led the development of the Wuhan-1 satellite, which was launched in May and has a panchromatic imaging resolution of 0.5 meters.

Li plans to donate all eight million yuan (about 1.1 million U.S. dollars) of the top sci-tech award money to support the cultivation of innovative talents.

"My duty is to impart knowledge," he said, "seeing my students make significant contributions is my greatest achievement."