Satellite breakthrough: China's laser tech spies from afar
Chinese scientists have developed a satellite featuring laser technology capable of capturing human facial details from over 100 kilometres away. This marks a hundredfold improvement in performance compared to leading surveillance cameras and traditional telescopes.
Chinese scientists have engineered a state-of-the-art satellite equipped with laser technology. The satellite, operating in low Earth orbit, can capture facial features from a distance exceeding 100 kilometres. According to the South China Morning Post, this groundbreaking achievement enhances performance by 100 times compared to previous spy cameras and telescopes. The research was published in the Chinese scientific journal Chinese Journal of Lasers.
New laser technology
Scientists from the Institute of Space Information Research at the Chinese Academy of Sciences conducted the research and testing. This technology, based on Synthetic Aperture Lidar (SAL), enables the creation of 2D and 3D images with unprecedented precision. SAL utilises the motion of an object, such as a satellite, to achieve higher resolution than traditional radar systems. The new system operates at optical wavelengths, producing more explicit images.
This technology has numerous applications, including monitoring foreign satellites with unmatched accuracy. During trials conducted over Qinghai Lake in northwestern China, the new system, based on Synthetic Aperture Lidar (SAL), demonstrated the capability to create two-dimensional or three-dimensional images. SAL employs the motion of an object, such as a satellite, to produce higher-resolution images than other radar beam-scanning systems.
During the test, using an array of reflective prisms placed 101 kilometres from the lidar system, the device detected details as small as 2 millimetres and measured distances with an accuracy of up to 15 millimetres. This is a significant advancement compared to previous achievements, such as a 2011 test conducted by Lockheed Martin, which achieved an azimuthal resolution of 20 millimetres from a distance of 1.6 kilometres, or the Chinese test, which achieved a resolution of 50 millimetres from a distance of 7 kilometres.
Tests conducted in ideal conditions
To reach this breakthrough, the Chinese team divided the laser beam powering the lidar system into a 4x4 microlens array, effectively increasing the system's optical aperture from 17 to 69 millimetres. This allowed researchers to overcome the trade-off between the field of view and aperture size, which has historically limited such camera systems.
However, as noted by the "South China Morning Post," the tests were conducted in ideal weather conditions. Atmospheric variables can significantly impact the system's precision and reliability.
