A method of spectrum estimation based on the genetic simulated annealing (GSA) algorithm is proposed, which is applied to retrieve the three-dimensional wind field of typhoon Nangka observed by our research group. Compared to the genetic algorithm (GA), the GSA algorithm not only extends the detection range and guarantees the accuracy of retrieval results but also demonstrates a faster retrieval speed. Experimental results indicate that both the GA and GSA algorithms can enhance the detection range by 35% more than the least squares method. However, the convergence speed of the GSA algorithm is 17 times faster than that of the GA, which is more beneficial for real-time data processing.

精确观测大气风场在气象、**、航空航天等领域具有十分重要的意义。相干测风激光雷达能够实时有效地进行大气矢量风场探测。为此研制出一款基于多普勒原理的相干测风激光雷达，并进行外场观测验证了其性能。该系统可探测垂直上空45～3000 m的水平风场以及垂直气流，最大可探测风速为60 m/s。分析比对了该雷达于2021年10月16日08：00―20日00：00在广州市黄埔区气象局观测的数据与同时段同地点微波风廓线雷达的观测数据，结果表明二者具有良好的一致性。重点分析了2021年10月18日10：00―20日00：00的典型观测数据，进一步验证了该相干测风激光雷达所测数据的准确性。该雷达在风场探测上的应用将为气象参数监测和预报精度的提高以及极端灾害性天气的预警提供实时数据支撑。

针对共振荧光测风雷达的探测需求，设计和研制了种子注入的Nd∶YAG电光调Q单频1 116 nm脉冲激光器，采用带偏置电压反馈的扫描-触发谐振探测技术，建立了1 116 nm单纵模振荡，并对中心频率稳定性进行分析。最终实现输出1 116 nm激光单脉冲能量6.48 mJ，重复频率60 Hz，输出线宽为33.2 MHZ，脉冲宽度为75.7 ns。通过波长计测量输出光波长，波长稳定在1 116.297 9 nm附近。利用外差拍频，测定120 min中心频率稳定性（均方根）为818.3 kHz。该激光器输出光通过三倍频可变换至372 nm，作为铁共振荧光多普勒测风激光雷达的发射光源，频率抖动量对应的风速测量误差小于1 m/s。

为分析死时间、暗计数等因素对单光子相干测速性能的影响，搭建了基于近红外单元单光子雪崩二极管探测器的外差相干测速实验系统，实验分析了探测器暗计数率和信号探测光子计数率对多普勒信息重建的影响，以及由探测器死时间决定的饱和计数率限制下的最优信号探测光子计数率。在1 μs探测器死时间、1 ms采集时间下，分别对1.8 kHz、52.4 kHz和194.4 kHz探测器暗计数率影响下的光子到达时间序列进行快速傅里叶变换，从频谱数据中提取拍频信号。实验结果表明，随着光子计数率的增加，相干拍频信号频谱信噪比逐渐增大而后趋于平稳，当接近饱和计数率时，在相干拍频信号频谱低频区域和拍频频率两侧出现了谐波分量，谐波频率间距与光子计数率数值基本相等，受谐波影响较小的最优光子计数率约为单光子探测器饱和计数率的90%。研究结果可为全光纤单光子多普勒测速雷达技术的发展和应用提供参考。

A new electronic speckle pattern interferometry method is proposed to realize in situ deformation measurements. The feature of the method is the combination of a high-speed camera and multiple laser Doppler vibrometers (LDVs) for synchronous measurements. The high-speed camera is used to record and select effective interferograms, while the LDVs are used to measure the rigid body displacement caused by vibrations. A series of effective interferograms with known shifted phase values are obtained to calculate the deformation phase. The experimental results show that the method performs well in measuring static and dynamic deformations with high accuracy in vibrating environments.

A sub-Nyquist radar receiver based on photonics-assisted compressed sensing is proposed. Cascaded dictionaries are applied to extract the delay and the Doppler frequency of the echo signals, which do not need to accumulate multiple echo periods and can achieve better Doppler accuracy. An experiment is performed. Radar echoes with different delays and Doppler frequencies are undersampled and successfully reconstructed to obtain the delay and Doppler information of the targets. Experimental results show that the average reconstruction error of the Doppler frequency is 5.33 kHz using an 8-μs radar signal under the compression ratio of 5. The proposed method provides a promising solution for the sub-Nyquist radar receiver.

为了探索基于氧气A带吸收谱线利用多普勒差分干涉仪实现对流层大气风场探测的技术可行性，建立了从大气吸收谱线入瞳临边辐射到干涉曲线的仪器响应函数数理模型，仿真分析干涉仪光学参数、滤光片参数、系统噪声、仪器稳定性和标准具离轴效应等对视线风速反演结果的影响，确定光学系统参数的最优取值范围。结果表明，对中心波长位于769 nm的氧气吸收线，当干涉仪非对称量取值6.5~6.7 mm，光谱分辨率取值0.49~0.51 cm-1，带通滤光片半波带宽取值0.12~0.21 nm，标准具间距取值0.8~1.4 mm，精细度系数取值30~100，标准具离轴角小于0.2°，标准具透射峰偏移小于0.018 cm-1，干涉图信噪比大于40倍时，风速反演精度优于8 m/s，研究结果可为被动式对流层风场探测以及相关仪器设计提供理论参考。