摘要
散斑噪声会影响调频连续波(FMCW)相干激光雷达的拍频信号质量,进而影响雷达的探测性能。为衡量该影响并优化系统设计,采用几何光学近似的方法对散射场进行了简化处理。通过蒙特卡罗模拟仿真建立了散斑噪声对系统拍频信号强度的影响模型,并优化了系统光学天线孔径的设计。系统测试实验结果表明,拍频信号的强度与粗糙面高度和波长的比值成负指数关系,且弱散射表面的信号强度衰减更快。实验结果与理论和仿真分析相吻合,优化设计后的系统可对存在散斑噪声的拍频信号进行有效探测,且其测距和测速误差分别小于1 cm和0.05 cm/s。
The characteristics of beat-frequency signal（BFS） and the detection performance of the frequency-modulated continuous-wave（FMCW） coherent lidar are influenced by speckle noise.In order to estimate the impact and improve the system′s property,the scattered field is simplified utilizing geometrical optics approximation.The impact model of BFS affected by speckle field is derived by Monte Carlo simulation,and the optical antenna′s aperture is optimized.The system experiment is carried out,and the results demonstrate that the BFS intensity has a negative exponential relationship with the ratio of the surface-roughness height to the square of light wavelength,and it decreases more rapidly with weak scattering surfaces.The experimental results are in good agreement with the theoretical analysis and numerical simulation results.After system optimization,the BFS with speckle noise can be detected effectively,and the system′s range and velocity measurement errors are less than 1 cm and 0.05 cm/s,respectively.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2011年第10期94-100,共7页
Chinese Journal of Lasers
基金
航天科技创新基金资助课题
关键词
相干光学
调频连续波激光雷达
散斑噪声
拍频信号
coherence optics
frequency-modulated continuous-wave lidar
speckle noise
beat-frequency signal
