by Riko Seibo
Tokyo, Japan (SPX) Nov 08, 2025
Researchers from the College of Science and Know-how of China, led by professors Jian-Wei Pan, Hai-Feng Jiang, and Qiang Zhang, have achieved nanometer-level absolute distance measurement over a 113-kilometer path utilizing a bistatic dual-comb ranging (BDCR) strategy. This method attained a precision of 82 nanometers inside 21 seconds, establishing a brand new customary for high-precision long-distance measurement.
Twin-comb ranging expertise combines time-of-flight measurement with part interferometry, supporting each excessive precision and an prolonged ambiguity vary. Earlier open-path high-precision ranging strategies have been restricted to lower than 10 kilometers as a consequence of transmission losses and noise, hardly ever reaching nanometer accuracy at ultra-long vary.
On this research, the workforce’s BDCR methodology surpassed conventional methods by supporting measurable distances 2.5 instances better than monostatic dual-comb ranging on the identical sensitivity. The experiment spanned 113 kilometers, utilizing high-power optical frequency combs, large-aperture telescopes, low-noise photodetectors, and exact knowledge acquisition methods to counter atmospheric loss.
Efficiency was verified by two unbiased methods working at totally different wavelengths. The BDCR achieved a precision of 11.5 micrometers at 1.3 milliseconds, 681 nanometers at 1 second, and 82 nanometers at 21 seconds. Air dispersion evaluation and artificial repetition fee strategies prolonged the paradox vary, enabling protection of greater than 100 kilometers.
This achievement allows developments in satellite tv for pc constellation alignment, topographic mapping, Earth gravity mannequin development, high-resolution house telescope arrays, and satellite-based gravity measurement in catastrophe areas. The findings are anticipated to assist satellite tv for pc formation flying and constellation navigation with considerably better accuracy.
Analysis Report:113 km absolute ranging with nanometer precision
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