Performance Analysis of Doppler Lidar

9307233 Frehlich Research是为了分析实际系统配置下的多普勒激光雷达的性能，包括折射湍流和探测器几何形状的影响。系统性能由信噪比和外差效率决定。我们将对实际和理想的多普勒激光雷达系统进行信噪比和外差效率的解析和数值计算。对于单元素和多元素探测器，将确定外差效率估计值的统计行为。当折射湍流很重要时，我们将从理论和数值模拟两个方面研究如何使用多元素探测器来改善系统性能。模拟还将给出真实多普勒激光雷达信号起伏的准确统计描述，这是由于随机气溶胶目标和折射湍流造成的。将研究多普勒激光雷达性能的不同物理机制，并确定简单分析结果有效的区域。计算将强调固态激光雷达系统的较短波长。在实际大气条件下，将从理论上确定风的变化对多普勒激光雷达传感体积的影响。新的数据分析技术将应用于多普勒激光雷达数据，以验证理论结果，并准确估计多普勒激光雷达信号的大气层去相关时间。这对于评估多普勒激光雷达速度估计的准确性是至关重要的。利用大气去相关计算的理论结果和实验测量结果，将确定不同波长和系统设计的多普勒激光雷达速度估计的性能。这项研究将有助于设计下一代用于大气遥感的固态多普勒激光雷达。***

9307233 Frehlich Research is proposed to analyze the performance of Doppler lidar for real system configurations, including the effects of refrctive turbulence and detector geometry. System performane is determined by the Signal to Noise Ratio(SNR) and the heterodyne efficiency. Analytic and numerical calculations of SNR and heterodyne efficiency for real and idealized Doppler lidar systems will be performed. The statistical behavior of estimates for heterodyne effciency will be determined for single element and multi-element detectors. The use of multi-element detectors for improving system performance when refractive turbulence is important will be investigated theoretically and with numerical simulations. The simulations will also produce accurate statistical description of real Doppler lidar signal fluctuations due to the random aerosol targets and refractive turbulence. The different physical mechanisms of Doppler lidar performance will be investigated and the regimes where simple analytic results are valid will be determined. The calculations will emphasize the shorter wavelenghts of solid state lidar systems. The effects of wind variations in the sensing volume of Doppler lidar will be determined theoretically for realistic atmospheric conditions. New data analysis techniques will be applied to Doppler lidar data to verify the theoretical results and produce accurate estimates of the atomospheric decorrelation time for Doppler lidar signals. This is essential for evaluating the accuracy of Doppler Lidar velocity estimates. The performace of Doppler Lidar velocity estimation for various wavelengths and system designs will be determined using the theoretical results of the atmospheric decorrelation calculations and the experimental measurements. This research will help design the next generation of solid state Doppler lidars for remote sensing of the atmosphere. ***