{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T05:07:41Z","timestamp":1768540061694,"version":"3.49.0"},"reference-count":48,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2023,11,3]],"date-time":"2023-11-03T00:00:00Z","timestamp":1698969600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["NRF-2012R1A3A1050386"],"award-info":[{"award-number":["NRF-2012R1A3A1050386"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We configured a long-distance ranging apparatus to test the principle of dual-comb time-of-flight measurement using ultrashort lasers. Emphasis was given to the evaluation of open-air performance quantitatively in terms of the measurement resolution and stability. The test results revealed that our dual-comb asynchronous optical pulse sampling permits micrometer-resolved ranging with a repeatability of 2.05 \u03bcm over a 648 m distance in dry weather conditions. Further atmospheric effects were evaluated in three different weather conditions with corresponding Allan deviations. Finally, the capability of simultaneous determination of multiple targets was verified with the potential of advanced industrial applications, such as manufacturing, surveying, metrology, and geodesy.<\/jats:p>","DOI":"10.3390\/s23218949","type":"journal-article","created":{"date-parts":[[2023,11,3]],"date-time":"2023-11-03T10:59:54Z","timestamp":1699009194000},"page":"8949","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Open-Air Testing of Dual-Comb Time-of-Flight Measurement"],"prefix":"10.3390","volume":"23","author":[{"given":"Wooram","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jaewon","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-9874-2407","authenticated-orcid":false,"given":"Jaeyoung","family":"Jang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2013-9443","authenticated-orcid":false,"given":"Jeong Seok","family":"Oh","sequence":"additional","affiliation":[{"name":"Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Yuseong-gu, Daejeon 34103, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9065-4611","authenticated-orcid":false,"given":"Seongheum","family":"Han","sequence":"additional","affiliation":[{"name":"Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Yuseong-gu, Daejeon 34103, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Seungman","family":"Kim","sequence":"additional","affiliation":[{"name":"Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials (KIMM), Yuseong-gu, Daejeon 34103, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4601-5377","authenticated-orcid":false,"given":"Heesuk","family":"Jang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4271-5771","authenticated-orcid":false,"given":"Young-Jin","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0235-1739","authenticated-orcid":false,"given":"Seung-Woo","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1016\/j.cirp.2015.05.009","article-title":"Measurement technologies for precision positioning","volume":"64","author":"Gao","year":"2015","journal-title":"CIRP Ann.-Manuf. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1126\/science.265.5171.482","article-title":"Lunar Laser Ranging: A Continuing Legacy of the Apollo Program","volume":"265","author":"Dickey","year":"1994","journal-title":"Science"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"712","DOI":"10.1088\/0957-0233\/11\/6\/314","article-title":"Laser-based distance measurement using picosecond resolution time-correlated single-photon counting","volume":"11","author":"Pellegrini","year":"2000","journal-title":"Meas. Sci. Technol."},{"key":"ref_4","first-page":"351","article-title":"Phase-measurement interferometry techniques","volume":"Volume 26","author":"Wolf","year":"1988","journal-title":"Progress in Optics"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1038\/nphoton.2009.86","article-title":"Metrology: Combs rule","volume":"3","author":"Kim","year":"2009","journal-title":"Nat. Photon."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1038\/nphoton.2011.38","article-title":"Searching for applications with a fine-tooth comb","volume":"5","author":"Newbury","year":"2011","journal-title":"Nat. Photon."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5512","DOI":"10.1364\/AO.39.005512","article-title":"High-accuracy measurement of 240-m distance in an optical tunnel by use of a compact femtosecond laser","volume":"39","author":"Minoshima","year":"2000","journal-title":"Appl. Opt."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Minoshima, K. (2010, January 20\u201324). High-precision absolute length metrology using fiber-based optical frequency combs. Proceedings of the 2010 International Conference on Electromagnetics in Advanced Applications (ICEAA), Sydney, Australia.","DOI":"10.1109\/ICEAA.2010.5650676"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"115302","DOI":"10.1088\/0957-0233\/21\/11\/115302","article-title":"Absolute distance measurement system using a femtosecond laser as a modulator","volume":"21","author":"Doloca","year":"2010","journal-title":"Meas. Sci. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"122403","DOI":"10.1117\/1.OE.53.12.122403","article-title":"Absolute distance measurement with extension of nonambiguity range using the frequency comb of a femtosecond laser","volume":"53","author":"Jang","year":"2014","journal-title":"Opt. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2140","DOI":"10.1364\/OL.38.002140","article-title":"Pulse-to-pulse alignment technique based on synthetic-wavelength interferometry of optical frequency combs for distance measurement","volume":"38","author":"Wu","year":"2013","journal-title":"Opt. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Kim, W., Fu, H., Lee, K., Han, S., Jang, Y.-S., and Kim, S.-W. (2020). Photonic Microwave Distance Interferometry Using a Mode-Locked Laser with Systematic Error Correction. Appl. Sci., 10.","DOI":"10.3390\/app10217649"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1364\/OE.10.000515","article-title":"Continuously tunable, precise, single frequency optical signal generator","volume":"10","author":"Jost","year":"2002","journal-title":"Opt. Express"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1515\/nanoph-2016-0019","article-title":"Optical Frequency Comb Generation based on Erbium Fiber Lasers","volume":"5","author":"Droste","year":"2016","journal-title":"Nanophotonics"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1007\/s10043-999-0449-x","article-title":"Fractional Fringe Order Method Using Fourier Analysis for Absolute Measurement of Block Gauge Thickness","volume":"6","author":"Tsai","year":"1999","journal-title":"Opt. Rev."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2715","DOI":"10.1364\/AO.47.002715","article-title":"High-accuracy absolute distance measurement using frequency comb referenced multiwavelength source","volume":"47","author":"Schuhler","year":"2008","journal-title":"Appl. Opt."},{"key":"ref_17","first-page":"5968","article-title":"Frequency-comb-referenced two-wavelength source for absolute distance measurement","volume":"14","author":"Schuhler","year":"2006","journal-title":"Opt. Express"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"9121","DOI":"10.1364\/OE.23.009121","article-title":"Absolute positioning by multi-wavelength interferometer referenced to the frequency comb of a femtosecond laser","volume":"23","author":"Wang","year":"2015","journal-title":"Opt. Express"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"31770","DOI":"10.1038\/srep31770","article-title":"Comb-referenced laser distance interferometer for industrial nanotechnology","volume":"6","author":"Jang","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5954","DOI":"10.1364\/OE.14.005954","article-title":"Absolute distance measurement by dispersive interferometry using a femtosecond pulse laser","volume":"14","author":"Joo","year":"2006","journal-title":"Opt. Express"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6549","DOI":"10.1364\/OE.19.006549","article-title":"Long distance measurement with femtosecond pulses using a dispersive interferometer","volume":"19","author":"Cui","year":"2011","journal-title":"Opt. Express"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"183901","DOI":"10.1103\/PhysRevLett.108.183901","article-title":"Many-Wavelength Interferometry with Thousands of Lasers for Absolute Distance Measurement","volume":"108","author":"Berg","year":"2012","journal-title":"Phys. Rev. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"14661","DOI":"10.1038\/srep14661","article-title":"Mode-resolved frequency comb interferometry for high-accuracy long distance measurement","volume":"5","author":"Berg","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"015202","DOI":"10.1088\/0957-0233\/27\/1\/015202","article-title":"Absolute distance measurement in a combined-dispersive inter-ferometer using a femtosecond pulse laser","volume":"27","author":"Wu","year":"2016","journal-title":"Meas. Sci. Technol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1038\/nphoton.2009.94","article-title":"Rapid and precise absolute distance measurements at long range","volume":"3","author":"Coddington","year":"2009","journal-title":"Nat. Photon."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"17324","DOI":"10.1364\/OE.17.017324","article-title":"A distance meter using a terahertz intermode beat in an optical frequency comb","volume":"17","author":"Yokoyama","year":"2009","journal-title":"Opt. Express"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"32044","DOI":"10.1364\/OE.23.032044","article-title":"Parameter optimization of a dual-comb ranging system by using a numerical simulation method","volume":"23","author":"Wu","year":"2015","journal-title":"Opt. Express"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"045201","DOI":"10.1088\/0957-0233\/24\/4\/045201","article-title":"Absolute distance measurement by dual-comb interferometry with adjustable synthetic wavelength","volume":"24","author":"Lee","year":"2013","journal-title":"Meas. Sci. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1364\/OL.29.001153","article-title":"Absolute measurement of a long, arbitrary distance to less than an optical fringe","volume":"29","author":"Ye","year":"2004","journal-title":"Opt. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.optlaseng.2018.05.002","article-title":"Absolute distance measurement using optical sampling by sweeping the repetition frequency","volume":"109","author":"Xue","year":"2018","journal-title":"Opt. Lasers Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2026","DOI":"10.1364\/OL.38.002026","article-title":"Comb-calibrated frequency-modulated continuous-wave ladar for absolute distance measurements","volume":"38","author":"Baumann","year":"2013","journal-title":"Opt. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"24914","DOI":"10.1364\/OE.22.024914","article-title":"Comb-calibrated laser ranging for three-dimensional surface profiling with micrometer-level precision at a distance","volume":"22","author":"Baumann","year":"2014","journal-title":"Opt. Express"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1038\/nphoton.2008.225","article-title":"Drift-free femtosecond timing synchronization of remote optical and microwave sources","volume":"2","author":"Kim","year":"2008","journal-title":"Nat. Photon."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1038\/nphoton.2010.175","article-title":"Time-of-flight measurement with femtosecond light pulses","volume":"4","author":"Lee","year":"2010","journal-title":"Nat. Photon."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"065203","DOI":"10.1088\/0957-0233\/23\/6\/065203","article-title":"High precision laser ranging by time-of-flight measurement of femtosecond pulses","volume":"23","author":"Lee","year":"2012","journal-title":"Meas. Sci. Technol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6597","DOI":"10.1364\/OE.22.006597","article-title":"Absolute distance measurement by dual-comb nonlinear asynchronous optical sampling","volume":"22","author":"Zhang","year":"2014","journal-title":"Opt. Express"},{"key":"ref_37","first-page":"1","article-title":"Compact Dual-Comb Absolute Distance Ranging with an Electric Reference","volume":"7","author":"Zhang","year":"2015","journal-title":"IEEE Photon. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"125201","DOI":"10.1088\/0957-0233\/25\/12\/125201","article-title":"Reliable non-ambiguity range extension with dual-comb simultaneous operation in absolute distance measurements","volume":"25","author":"Zhang","year":"2014","journal-title":"Meas. Sci. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"14057","DOI":"10.1364\/OE.23.014057","article-title":"Effect of timing jitter on time-of-flight distance measurements using dual femtosecond lasers","volume":"23","author":"Shi","year":"2015","journal-title":"Opt. Express"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"25874","DOI":"10.1364\/OE.23.025874","article-title":"Parallel determination of absolute distances to multiple targets by time-of-flight measurement using femtosecond light pulses","volume":"23","author":"Han","year":"2015","journal-title":"Opt. Express"},{"key":"ref_41","first-page":"1","article-title":"Timing Jitter of the Dual-Comb Mode-Locked Laser: A Quantum Origin and the Ultimate Effect on High-Speed Time-and Frequency-Domain Metrology","volume":"24","author":"Shi","year":"2018","journal-title":"IEEE J. Sel. Top. Quantum Electron."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"807","DOI":"10.1364\/OL.43.000807","article-title":"Absolute distance measurement by multi-heterodyne interferometry using an electro-optic triple comb","volume":"43","author":"Zhao","year":"2018","journal-title":"Opt. Lett."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"B27","DOI":"10.1364\/JOSAA.395157","article-title":"Absolute laser ranging by time-of-flight measurement of ultrashort light pulses","volume":"37","author":"Kim","year":"2020","journal-title":"J. Opt. Soc. Am. A"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"105102","DOI":"10.1088\/1612-2011\/12\/10\/105102","article-title":"Polarization maintaining linear cavity Er-doped fiber femtosecond laser","volume":"12","author":"Jang","year":"2015","journal-title":"Laser Phys. Lett."},{"key":"ref_45","first-page":"9","article-title":"The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers","volume":"434","author":"Kolmogorov","year":"1890","journal-title":"Proc. R. Soc. A Math. Phys. Eng. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"023805","DOI":"10.1103\/PhysRevA.89.023805","article-title":"Optical phase noise from atmospheric fluctuations and its impact on optical time-frequency transfer","volume":"89","author":"Sinclair","year":"2014","journal-title":"Phys. Rev. A"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"4438","DOI":"10.1038\/s41467-019-12443-8","article-title":"Free-space transfer of comb-rooted optical frequencies over an 18 km open-air link","volume":"10","author":"Kang","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_48","unstructured":"Andrews, L.C., and Phillips, R.L. (1998). Laser Beam Propagation through Random Media, SPIE Optical Engineering Press."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/8949\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:16:31Z","timestamp":1760130991000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/8949"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,3]]},"references-count":48,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2023,11]]}},"alternative-id":["s23218949"],"URL":"https:\/\/doi.org\/10.3390\/s23218949","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,3]]}}}