Citation: | ZHANG Jun-rui, ZHAO Yu-ling, YANG Le-qiang, LIU Jie, WANG Wen-yu, LI Zheng-wei, WANG Jian-li, CHEN Tao. Measurement of atmospheric coherence length for extended targets based on wavefront structure function[J]. Chinese Optics. doi: 10.37188/CO.2024-0215 |
Atmospheric coherence length is a critical indicator of the impact of atmospheric turbulence on free-space optical communication links. This paper proposes a novel strategy for measuring atmospheric coherence length by utilizing extended targets as the information source. Specifically, the method integrates the wavefront structure function approach with the extended target offset algorithm to directly estimate the atmospheric coherence length. Traditional methods, such as the Differential Image Motion Monitor (DIMM), typically rely on guide star targets, which are difficult to set appropriately in horizontal communication links, thereby limiting their effectiveness in practical applications. In contrast, employing extended targets as direct detection targets provides a feasible solution for measuring atmospheric coherence length. The paper first reviews the principles and current research status of mainstream algorithms, emphasizing the reliance of existing algorithms on guide star targets and their limitations in horizontal links. Subsequently, we propose a new measurement scheme that combines the improved normalized cross-correlation algorithm with the wavefront structure function method to estimate atmospheric coherence length under extended targets scenarios. In comparison to traditional measurement methods, our approach enables coherence length measurement based on extended targets in horizontal links, thereby significantly reducing system complexity and equipment costs. To validate the effectiveness and measurement accuracy of the proposed method, both simulations and experiments were designed and conducted. The results demonstrate that the coherence length values measured by this method are highly consistent with those obtained using the DIMM method and the wavefront phase variance method, with a measurement accuracy error of approximately 4%. This indicates that the proposed method can effectively assess atmospheric coherence length, thereby providing a valuable reference for enhancing the reliability of free-space laser communication systems.
[1] |
GUIOMAR F P, FERNANDES M A, NASCIMENTO J L, et al. Coherent free-space optical communications: opportunities and challenges[J]. Journal of Lightwave Technology, 2022, 40(10): 3173-3186. doi: 10.1109/JLT.2022.3164736
|
[2] |
刘恒瑞. 自由空间光通信系统中的信道预测技术研究[D]. 北京: 北京邮电大学, 2024.
LIU H R. Channel prediction techniques in free-space optical communication systems[D]. Beijing: Beijing University of Posts and Telecommunications, 2024. (in Chinese).
|
[3] |
JAHID A, ALSHARIF M H, HALL T J. A contemporary survey on free space optical communication: Potentials, technical challenges, recent advances and research direction[J]. Journal of Network and Computer Applications, 2022, 200: 103311. doi: 10.1016/j.jnca.2021.103311
|
[4] |
陈丹, 陈昊雅, 王明军, 等. 非理想信道下自由空间光通信自适应星座几何整形[J]. 光学学报,2025,45(3):0306004. doi: 10.3788/AOS241470
CHEN D, CHEN H Y, WANG M J, et al. Adaptive constellation geometry shaping for free space optical communication in non-ideal channels[J]. Acta Optica Sinica, 2025, 45(3): 0306004. (in Chinese). doi: 10.3788/AOS241470
|
[5] |
朱嘉康, 安其昌, 杨飞. 大口径望远镜镜面视宁度检测方法综述[J]. 红外与激光工程,2023,52(2):20220488. doi: 10.3788/IRLA20220488
ZHU J K, AN Q CH, YANG F. Review on the measurement methods of mirror seeing of large-aperture telescope[J]. Infrared and Laser Engineering, 2023, 52(2): 20220488. (in Chinese). doi: 10.3788/IRLA20220488
|
[6] |
FRIED D L. Statistics of a geometric representation of wavefront distortion[J]. Journal of the Optical Society of America, 1965, 55(11): 1427-1435. doi: 10.1364/JOSA.55.001427
|
[7] |
LI M, ZHANG P X, HAN J W. Methods of atmospheric coherence length measurement[J]. Applied Sciences, 2022, 12(6): 2980. doi: 10.3390/app12062980
|
[8] |
GRIFFITHS R, BARDOU L, BUTTERLEY T, et al. A comparison of next-generation turbulence profiling instruments at Paranal[J]. Monthly Notices of the Royal Astronomical Society, 2024, 529(1): 320-330. doi: 10.1093/mnras/stae434
|
[9] |
SABIL M, HABIB A, BENKHALDOUN Z. Interferential seeing monitor, a seeing monitor for atmospheric turbulence studies: calibration with the differential image motion monitor[J]. Monthly Notices of the Royal Astronomical Society, 2020, 500(2): 1884-1888. doi: 10.1093/mnras/staa2400
|
[10] |
TILLAYEV Y, AZIMOV A, EHGAMBERDIEV S, et al. Astronomical seeing and meteorological parameters at maidanak observatory[J]. Atmosphere, 2023, 14(2): 199. doi: 10.3390/atmos14020199
|
[11] |
SUBRAMANIAN S K, RENGASWAMY S, DESHMUKH P G, et al. Daytime turbulence strength profile measurement at Kodaikanal observatory[J]. Journal of Astronomical Telescopes, Instruments, and Systems, 2024, 10(3): 039004.
|
[12] |
JACKSON O, VAN KOOTEN M A M, PERERA S, et al. SHIMM as an atmospheric profiler on the nickel telescope[J]. Proceedings of SPIE, 2023, 12680: 126801V.
|
[13] |
PERERA S, WILSON R W, BUTTERLEY T, et al. SHIMM: a versatile seeing monitor for astronomy[J]. Monthly Notices of the Royal Astronomical Society, 2023, 520(4): 5475-5486. doi: 10.1093/mnras/stad339
|
[14] |
ANDRADE P P, GARCIA P J V, CORREIA C M, et al. Estimation of atmospheric turbulence parameters from Shack–Hartmann wavefront sensor measurements[J]. Monthly Notices of the Royal Astronomical Society, 2019, 483(1): 1192-1201. doi: 10.1093/mnras/sty3181
|
[15] |
SAUVAGE C, ROBERT C, MUGNIER L M, et al. Near ground horizontal high resolution
|
[16] |
HE Y, BAO M D, CHEN Y W, et al. Accuracy characterization of Shack–Hartmann sensor with residual error removal in spherical wavefront calibration[J]. Light: Advanced Manufacturing, 2023, 4(4): 36.
|
[17] |
ARISTIDI E, ZIAD A, CHABÉ J, et al. A generalized differential image motion monitor[J]. Monthly Notices of the Royal Astronomical Society, 2019, 486(1): 915-925. doi: 10.1093/mnras/stz854
|
[18] |
DIBAEE B, SHOMALI R, KHALILZADEH J, et al. 4-aperture differential image motion monitor as a new approach for estimating atmospheric turbulence parameters[J]. Journal of Modern Optics, 2019, 66(7): 753-763. doi: 10.1080/09500340.2019.1567843
|
[19] |
王子跃, 任德清. 差分像运动视宁度优化监测法[J]. 天文研究与技术,2019,16(1):114-122.
WANG Z Y, REN D Q. Improved to differential image motion monitor[J]. Astronomical Research & Technology, 2019, 16(1): 114-122. (in Chinese).
|
[20] |
KORNILOV V, SAFONOV B. Wave propagation effect on differential image motion monitor measurements[J]. Monthly Notices of the Royal Astronomical Society, 2019, 488(1): 1273-1281. doi: 10.1093/mnras/stz1783
|
[21] |
毛红敏, 丁致雅, 杨燕燕, 等. 大气湍流对高分辨率遥感卫星的成像影响研究[J]. 中国光学(中英文),2024,17(1):167-177. doi: 10.37188/CO.2023-0083
MAO H M, DING Z Y, YANG Y Y, et al. Effect of atmospheric turbulence on imaging quality of high-resolution remote sensing satellites[J]. Chinese Optics, 2024, 17(1): 167-177. (in Chinese). doi: 10.37188/CO.2023-0083
|
[22] |
KORNILOV V, SAFONOV B. Differential image motion in the short-exposure regime[J]. Monthly Notices of the Royal Astronomical Society, 2011, 418(3): 1878-1888. doi: 10.1111/j.1365-2966.2011.19604.x
|
[23] |
MACATANGAY R, RATTANASOON S, BUTTERLEY T, et al. Seeing and turbulence profile simulations over complex terrain at the Thai national observatory using a chemistry-coupled regional forecasting model[J]. Monthly Notices of the Royal Astronomical Society, 2024, 530(2): 1414-1423. doi: 10.1093/mnras/stae727
|
[24] |
赵文栋, 杨飞, 安其昌. 面向大口径地基望远镜视宁度检测方法综述[J]. 激光与红外,2023,53(9):1299-1308. doi: 10.3969/j.issn.1001-5078.2023.09.001
ZHAO W D, YANG F, AN Q CH. Review on the inspection methods of visibility for large aperture ground based telescope[J]. Laser & Infrared, 2023, 53(9): 1299-1308. (in Chinese). doi: 10.3969/j.issn.1001-5078.2023.09.001
|
[25] |
ZURASKI S M, BEECHER E, MCCRAE J E, et al. Turbulence profiling using pupil plane wavefront data derived Fried parameter values for a dynamically ranged rayleigh beacon[J]. Optical Engineering, 2020, 59(8): 081807.
|
[26] |
仇陈祥. 应用于船载平台的湍流廓线激光雷达研制[D]. 合肥: 中国科学技术大学, 2023.
QIU CH X. Development of Lidar System for Monitoring Turbulent Profiles on Shipborne Platform[D]. Hefei: University of Science and Technology of China, 2023. (in Chinese).
|
[27] |
陈亮, 周孟哲, 陈禾. 一种结合边缘区域和互相关的图像配准方法[J]. 北京理工大学学报,2016,36(3):320-325.
CHEN L, ZHOU M ZH, CHEN H. A method for image registration combined by edge region and cross correlation[J]. Transactions of Beijing Institute of Technology, 2016, 36(3): 320-325. (in Chinese).
|
[28] |
CANNY J. A computational approach to edge detection[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1986, PAMI-8(6): 679-698. doi: 10.1109/TPAMI.1986.4767851
|
[29] |
CHARNOTSKII M. Four methods for generation of turbulent phase screens: comparison[J]. arXiv: 1911.09185, 2019. (查阅网上资料, 不确定文献类型及格式是否正确, 请确认) .
|
[30] |
陈浩, 宣丽, 胡立发, 等. 大气相干长度的稳定测量[J]. 光学 精密工程,2013,21(4):911-918.
CHEN H, XUAN L, HU L F, et al. Steady measurement of atmospheric turbulence coherence length[J]. Optics and Precision Engineering, 2013, 21(4): 911-918. (in Chinese).
|