{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T11:06:40Z","timestamp":1790075200720,"version":"4.0.1"},"reference-count":23,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T00:00:00Z","timestamp":1789862400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) has become increasingly significant for long-distance ranging fields. However, the beat signal is vulnerable to noise interference during detection, resulting in a low signal-to-noise ratio (SNR) and inaccurate ranging results. Although traditional methods have improved accuracy through various denoising and spectral analysis algorithms, they often struggle to maintain robust performance in long-range scenarios under low-SNR conditions. To address this challenge, this paper proposes the HOIGL, a hybrid frequency estimation algorithm which integrates Orthogonal Matching Pursuit (OMP) for initial value guidance and Gray Wolf Optimization (GWO) for local search. Specifically, by leveraging the frequency-domain sparsity of the signal, OMP performs piecewise sparse representation to yield a coarse initial frequency, within which GWO conducts a refined continuous local search to overcome dictionary discretization bias based on a custom fitness function. Monte Carlo simulations in MATLAB demonstrate that the proposed algorithm achieves an RMSE of 2.63 m compared to over 84.34 m for other methods at \u221220 dB SNR, while maintaining a low and stable processing time of around 0.498 s. Finally, fiber-optic-link experimental results verify the performance of HOIGL for hundred-meter-scale range detection.<\/jats:p>","DOI":"10.3390\/s26185959","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T10:21:48Z","timestamp":1790072508000},"page":"5959","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Hybrid Frequency Estimation Framework for Long-Range FMCW LiDAR Under Low-SNR Conditions"],"prefix":"10.3390","volume":"26","author":[{"given":"Yating","family":"Fang","sequence":"first","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Xiaohai","family":"Yu","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"given":"Chaochao","family":"Zhang","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Jia","family":"He","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Yuanying","family":"Zhang","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"}]},{"given":"Hua","family":"Zheng","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"given":"Xiaoqin","family":"Zhu","sequence":"additional","affiliation":[{"name":"Fujian Provincial Key Laboratory for Photonics Technology, Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350117, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1038\/s43586-025-00446-3","article-title":"Light Detection and Ranging of Natural Systems","volume":"5","author":"Irwin","year":"2025","journal-title":"Nat. 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