Modeling of direct detection Doppler wind lidar. I. The edge technique.
Modeling of direct detection Doppler wind lidar. I. The edge technique.
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DOI：
10.1364/ao.37.006480
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发表时间：
1998-09
期刊：
影响因子：
1.9
通讯作者：
J. Mckay
中科院分区：
文献类型：
--
作者：
J. Mckay
基于Fabry-Perot标准具传递函数与高斯谱源的卷积，建立了基于边缘滤波技术的多普勒测风激光雷达散粒噪声受限测量精度的解析模型。瑞利后向散射公式产生的理论灵敏度与标准具参数的映射，允许设计优化，并表明最佳系统将有一个多普勒测量不确定性不优于约2.4倍，一个完美的，无损的接收器。模型的扩展，包括有限的标准具孔径的影响，导致匹配光收集光学所需的最小孔径的条件。结果表明，根据工作点的选择，标准具孔径精细度必须为4-15，以避免测量精度的下降。一个方便的，封闭形式的表达式的测量精度得到光谱窄的反向散射，并被证明是有用的反向散射是光谱宽以及。模型扩展到包括外部噪声，如太阳背景或瑞利背景气溶胶多普勒激光雷达。模型预测与实验的比较还不可能，但与麦吉尔和Spurrne的详细仪器建模的比较显示出令人满意的一致性。这里推导出的模型将更方便地实现比麦吉尔和Sperrne的，更容易允许物理的见解的优化和限制的双边技术。
Analytic models, based on a convolution of a Fabry-Perot etalon transfer function with a Gaussian spectral source, are developed for the shot-noise-limited measurement precision of Doppler wind lidars based on the edge filter technique by use of either molecular or aerosol atmospheric backscatter. The Rayleigh backscatter formulation yields a map of theoretical sensitivity versus etalon parameters, permitting design optimization and showing that the optimal system will have a Doppler measurement uncertainty no better than approximately 2.4 times that of a perfect, lossless receiver. An extension of the models to include the effect of limited etalon aperture leads to a condition for the minimum aperture required to match light collection optics. It is shown that, depending on the choice of operating point, the etalon aperture finesse must be 4-15 to avoid degradation of measurement precision. A convenient, closed-form expression for the measurement precision is obtained for spectrally narrow backscatter and is shown to be useful for backscatter that is spectrally broad as well. The models are extended to include extrinsic noise, such as solar background or the Rayleigh background on an aerosol Doppler lidar. A comparison of the model predictions with experiment has not yet been possible, but a comparison with detailed instrument modeling by McGill and Spinhirne shows satisfactory agreement. The models derived here will be more conveniently implemented than McGill and Spinhirne's and more readily permit physical insights to the optimization and limitations of the double-edge technique.