Researchers from the University of Science and Technology 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 using a bistatic dual-comb ranging (BDCR) approach. This technique attained a precision of 82 nanometers within 21 seconds, establishing a new standard for high-precision long-dis by Riko Seibo
Tokyo, Japan (SPX) Nov 08, 2025
Researchers from the University of Science and Technology 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 using a bistatic dual-comb ranging (BDCR) approach. This technique attained a precision of 82 nanometers within 21 seconds, establishing a new standard for high-precision long-distance measurement.
Dual-comb ranging technology combines time-of-flight measurement with phase interferometry, supporting both high precision and an extended ambiguity range. Previous open-path high-precision ranging methods were limited to less than 10 kilometers due to transmission losses and noise, rarely reaching nanometer accuracy at ultra-long range.
In this study, the team's BDCR method surpassed traditional systems by supporting measurable distances 2.5 times greater than monostatic dual-comb ranging at the same sensitivity. The experiment spanned 113 kilometers, using high-power optical frequency combs, large-aperture telescopes, low-noise photodetectors, and precise data acquisition systems to counter atmospheric loss.
Performance was verified through two independent systems operating at 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 analysis and synthetic repetition rate techniques extended the ambiguity range, enabling coverage of more than 100 kilometers.
This achievement enables advancements in satellite constellation alignment, topographic mapping, Earth gravity model construction, high-resolution space telescope arrays, and satellite-based gravity measurement in disaster areas. The findings are expected to support satellite formation flying and constellation navigation with substantially greater accuracy.
Research Report:113 km absolute ranging with nanometer precision
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