China just shook Starlink with a 5 times faster laser from a distance of 36,000km
&imwidth=600&imheight=450&format=webp&quality=medium "China just shook Starlink with a 5 times faster laser from a distance of 36,000km")
Satellite signal representative image Photograph: (Unsplash)
Chinese researchers achieve a 1Gbps satellite laser downlink from 36,000 kilometres above Earth using a 2-watt laser. This achievement has placed them far ahead of Starlink speeds with record-breaking efficiency.
China has achieved a remarkable feat in the field of satellite communications. From a satellite parked in the geostationary orbit (GEO)—approximately 36,000 km above Earth — scientists successfully established a 1Gbps laser downlink using only a 2-watt laser. They beat Starlink with this achievement whose satellites operate in low-Earth orbit, only a few hundred kilometres above Earth. The beam from the satellite did not arrive neat and steady, and instead scattered and changed form in the atmosphere. The Chinese signal travelled over 60 times further than a Starlink satellite, and yet was around five times faster than the speeds Elon Musk's company has managed to achieve. Chinese researchers from Peking University of Posts and Telecommunications and the Chinese Academy of Sciences achieved clean data in a receiver from a beam that witnessed atmospheric distortion.
Making distorted signal clean and usable
Even though the laser link was travelling from a much farther distance than regular satellites, that wasn't the main challenge. The researchers had to get a stable, high-speed downlink that could survive the last stretch through the moving air above the observatory. Here, the beam lost its clean form, and the download could have become unusable. For this, they used a specialised ground system at the Lijiang Observatory. They placed a 1.8-meter telescope equipped with 357 micro-mirrors that were adjusted in real-time to reshape the incoming light and correct for atmospheric distortion. They combined adaptive optics that corrects distortions with mode diversity reception that collects and processes scattered signal components. The system split the signal into eight channels, identified the strongest paths, and combined them for decoding. The proportion of usable signal increased from 72% to 91.1%.
Distance of the laser signal
Trending Stories
&im=FitAndFill=(700,400))
)
)
)
)
)
)
)
)
)
)
)
)
)
)
&im=FitAndFill=(700,400))
)
)
)
)
)
)
)
)
)
)
)
)
)
&im=FitAndFill=(700,400))
The other commendable aspect is the speed with which the signal reached Earth despite how far it was coming from. According to the research led by Wu Jian and published in Acta Optica Sinica, the team recorded a 1Gbps laser downlink from geostationary orbit using a 2-watt laser. This was five times faster than Starlink, and like sending an HD movie from Shanghai to Los Angeles in less than five seconds, Daily Galaxy reported. The power level was another standout aspect, as a 2-watt transmitter compares to a night light. Long-range communications systems require much heavier power.
