According to reports, China has made another significant breakthrough in laser communication technology by successfully conducting its first 100Gbps ultra-high-speed satellite-to-ground laser transmission test for high-resolution remote sensing imagery. The South China Morning Post (SCMP) reported on January 2 that this marks a “breakthrough development” in China’s satellite-to-ground laser communication capabilities.
The official WeChat account of “Jilin-1” stated that this test is a major achievement for Chang Guang Satellite Technology Co., Ltd. (hereafter referred to as “Chang Guang Satellite”), following its earlier successes in 10Gbps satellite-to-ground and 100Gbps inter-satellite laser communication tests. This accomplishment signifies an important step toward building an ultra-high-speed optical network for integrated inter-satellite and satellite-to-ground communications.
Advancing Beyond Starlink
Chang Guang Satellite, renowned as the pioneer of China’s commercial satellite industry, has achieved this milestone with its advanced laser communication technology. Wang Xingxing, the company’s ground station laser communication technology lead, told the SCMP that this progress places Chang Guang Satellite ahead of SpaceX’s Starlink in satellite-to-ground laser communication capabilities.
“Achieving a 100Gbps transmission rate from satellites to Earth is akin to upgrading a single-lane highway into a multi-thousand-lane superhighway, enabling the transfer of 10 full-length movies in just one second,” Wang proudly noted. “While Starlink has demonstrated its inter-satellite laser communication system, it has yet to deploy satellite-to-ground laser communication technology. We believe they may have the capability, but we’ve already started large-scale deployment.”
Wang further revealed that Chang Guang Satellite plans to equip all satellites in the Jilin-1 constellation with these laser communication devices to improve efficiency. The goal is to expand the constellation to 300 satellites by 2027. Additionally, multiple laser communication ground stations are planned nationwide to enhance remote sensing image data collection.
Overcoming Challenges in Laser Communication
In December 2024, Chang Guang Satellite announced the success of its first 100Gbps ultra-high-speed satellite-to-ground laser transmission test, conducted using its self-developed vehicle-mounted laser communication ground station and the laser terminal aboard the Jilin-1 Platform 02A02 satellite. The test also successfully captured high-resolution remote sensing images, validating the feasibility and advanced nature of the technology.
The company’s team spent two years optimizing its vehicle-mounted ground station, overcoming critical challenges such as atmospheric channel compensation, high-precision time-frequency synchronization, Doppler shift dynamic correction, high-sensitivity demodulation, and precise beam tracking and pointing. These advancements resolved issues like signal distortion caused by atmospheric turbulence, frequency drift due to high-speed relative motion between satellites and ground, weak signal detection, and ultra-precise beam tracking, ultimately establishing a highly sensitive, long-range coherent laser communication link.
In collaboration with Beijing University of Posts and Telecommunications, Chang Guang Satellite also validated and advanced mode diversity reception technology, further ensuring the stability and reliability of laser signal transmission.
Mobile Ground Stations and Compact Laser Terminals
Unlike conventional stationary ground receivers, the Chinese team mounted the observation station on a truck, enhancing mobility and speeding up deployment. The self-developed laser communication terminal is backpack-sized, and the satellite carrying the terminal—Jilin-1 Platform 02A02—was launched in June 2023.
This satellite was part of a record-breaking launch that sent 41 satellites into orbit in a single mission, setting a new benchmark for China’s aerospace sector. The mission also marked a milestone in the Jilin-1 constellation project, achieving its interim goal of deploying over 100 satellites in orbit.
Implications for High-Resolution Remote Sensing and Beyond
As of November 2024, the Jilin-1 constellation had 117 satellites in orbit, making it the world’s largest sub-meter commercial remote sensing satellite constellation. With the ability to capture ultra-high-resolution images, the constellation’s capabilities have been significantly enhanced.
Chang Guang Satellite has developed the capability to manufacture very high-resolution optical remote sensing satellites and mastered 100Gbps laser communication for both satellite-to-ground and inter-satellite links. These advancements enable the construction of a high-speed laser data transmission network, opening significant opportunities for China’s remote sensing satellite network.
Compared to existing remote sensing satellites, the data volume generated by ultra-high-resolution satellites will increase severalfold. The breakthrough in ultra-high-speed laser communication technology greatly improves data transmission efficiency, providing robust support for the rapid relay of massive remote sensing imagery.
Broader Applications for Remote Sensing and Satellite Internet
Wang Xingxing highlighted that these technological advancements lay the groundwork for deploying and efficiently operating next-generation remote sensing constellations. Fast data relay capabilities will better serve disaster monitoring, national defense, smart cities, environmental protection, emergency response, and other sectors. They will also pave the way for extending remote sensing data applications to broader consumer use cases.
Additionally, ultra-high-speed laser communication technology can contribute to the construction of China’s integrated satellite internet system. This system aims to eliminate bottlenecks in data relay between satellite users and ground networks, providing broader bandwidth and higher data transmission rates. Such advancements will support the evolution from 5G NTN (Non-Terrestrial Network) to 6G satellite internet development.
