On August 13, 2023, a Long March-3B rocket launched the civilian radar observation satellite Ludi Tance 4 01 (LT-4 01) into space from the Xichang Cosmodrome. This device became the world's first geostationary Earth observation satellite. The technology was proposed in the United States in 1978, but China was the first to put it into practice, which brought the Celestial Empire to a leading position in radar technology.
Experts associate the declassification of the Ludi Tantse-4 mission with China's desire to demonstrate its superiority over Western partners in the field of high technology and space. The publication of a series of scientific articles on the project in the journal Space Science and Technology helps to clarify a number of features of the radar's operation in geostationary orbit (GEO). It uses synthetic aperture radar (SAR) technology and provides continuous monitoring of one third of the planet's surface from an altitude of 36,000 km.
The radar monitors the Asia-Pacific region around the clock, which is causing concern among neighboring countries and the United States, although the officially stated purpose of its work is earthquake prevention, as well as assistance in agriculture and forestry.
According to previous publications, LT-4 01 is able to distinguish objects on Earth up to 20 meters in size. Achieving such resolution with GEO requires the development of a whole range of technologies and solutions, including “summation“ in several beams into space, vaguely reminiscent of the technology of the Death Star from “Star Wars“. Unlike low-orbit remote sensing satellites, which provide more detailed images, LT-4 01 has significantly greater surface coverage, although its data takes longer to process.
To precisely guide the radar from geostationary orbit, Chinese scientists have developed unique stabilization mechanisms and signal processing algorithms. It is these algorithms that are the main value of LT-4 01, as they allow the reconstruction of highly distorted and partially blurred images of the planet's surface.
“By declassifying the core technologies, China has demonstrated to the world its superiority in electronic warfare“, says a Chinese researcher who requested anonymity. “Like the open-source models of artificial intelligence company DeepSeek, this will force competitors to try to catch up in areas where China has structural advantages.“