Chinese scientists managed to transmit information from geostationary orbit to Earth at a speed of 1 Gbps, which is five times faster than Starlink. For this, a laser with a power of only 2 W was used. About this informs South China Morning Post.
The experiment was conducted at an observatory in Lijiang (southwest China) using a 1.8-meter telescope aimed at a satellite at an altitude of 36,705 km. 357 micromirrors were installed inside the telescope, which compensated for the distortion of the wavefront caused by atmospheric turbulence.
According to the researchers, traditional methods—adaptive optics (AO) and multimode reception (MDR)—alone did not provide stable signal transmission. A team at Beijing University of Posts and Telecommunications combined these approaches, resulting in a significant improvement in signal quality even at very low power.
Data transmission was carried out through a multimode optical channel. Thanks to a special “path-picking” algorithm, the three strongest signals from eight basic channels were selected in real time and combined into a single stream with minimal loss.
The test results showed that the probability of receiving a stable signal increased from 72% to 91.1%. This is important for systems where delays and errors are unacceptable, such as in military or interplanetary communications.
It will be recalled that in 2020, China set a record by transmitting data at a speed of 10 Gbps from the Shijian-20 satellite. However, the exact characteristics of that mission remain classified. According to some reports, American satellites tried to track the Shijian-20, but the Chinese apparatus changed its orbit to avoid observation.
