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Publication Citation: Rapid and precise absolute distance measurements at long range

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Author(s): Ian R. Coddington; William C. Swann; Ljerka Nenadovic; Nathan R. Newbury;
Title: Rapid and precise absolute distance measurements at long range
Published: June 01, 2009
Abstract: The ability to determine absolute distance to an object is one of the most basic measurements of remote sensing. High precision ranging has important applications in both large-scale manufacturing and in future tight formation-flying satellite missions, where rapid and precise measurements of absolute distance are critical for maintaining the relative pointing and position of the individual satellites. Using two coherent broadband fibre-laser frequency comb sources, we demonstrate a coherent laser ranging system that combines the advantages of time-of-flight and interferometric approaches to provide absolute distance measurements, simultaneously from multiple reflectors, and at low power. The pulse time-of-flight yields a precision of 3 mm with an ambiguity range of 1.5m in 200ms. Through the optical carrier phase, the precision is improved to better than 5 nm at 60 ms, and through the radio-frequency phase the ambiguity range is extended to 30 km, potentially providing 2 parts in 1013 ranging at long distances.
Citation: Nature Photonics
Volume: 3
Pages: pp. 351 - 356
Keywords: frequency comb;formation-flying;ranging
Research Areas: Optical Metrology, Length, Remote Sensing
PDF version: PDF Document Click here to retrieve PDF version of paper (392KB)