Giles J W, Bankman I N, Sova R M, Morgan T R, Duncan D D, Millard J A, Green W J, Marcotte F J
The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, Maryland 20723, USA.
Appl Opt. 2008 Aug 1;47(22):4085-93. doi: 10.1364/ao.47.004085.
When lidar pulses travel through a short path that includes a relatively high concentration of aerosols, scattering phenomena can alter the power and temporal properties of the pulses significantly, causing undesirable effects in the received pulse. In many applications the design of the lidar transmitter and receiver must consider adverse environmental aerosol conditions to ensure the desired performance. We present an analytical model of lidar system operation when the optical path includes aerosols for use in support of instrument design, simulations, and system evaluation. The model considers an optical path terminated with a solid object, although it can also be applied, with minor modifications, to cases where the expected backscatter occurs from nonsolid objects. The optical path aerosols are characterized by their attenuation and backscatter coefficients derived by the Mie theory from the concentration and particle size distribution of the aerosol. Other inputs include the lidar system parameters and instrument response function, and the model output is the time-resolved received pulse. The model is demonstrated and experimentally validated with military fog oil smoke for short ranges (several meters). The results are obtained with a lidar system operating at a wavelength of 0.905 microm within and outside the aerosol. The model goodness of fit is evaluated using the statistical coefficient of determination whose value ranged from 0.88 to 0.99 in this study.
当激光雷达脉冲穿过一条包含相对高浓度气溶胶的短路径时,散射现象会显著改变脉冲的功率和时间特性,从而在接收脉冲中产生不良影响。在许多应用中,激光雷达发射器和接收器的设计必须考虑不利的环境气溶胶条件,以确保所需的性能。我们提出了一种激光雷达系统运行的分析模型,当光路中包含气溶胶时,可用于支持仪器设计、模拟和系统评估。该模型考虑了以固体物体为终点的光路,不过经过微小修改后,它也可应用于预期后向散射来自非固体物体的情况。光路中的气溶胶通过米氏理论根据气溶胶的浓度和粒径分布推导得出的衰减系数和后向散射系数来表征。其他输入包括激光雷达系统参数和仪器响应函数,模型输出是时间分辨的接收脉冲。该模型通过军事用雾油烟雾在短距离(几米)内进行了演示和实验验证。结果是在一个工作波长为0.905微米的激光雷达系统在气溶胶内外获得的。使用决定系数对模型的拟合优度进行评估,在本研究中其值范围为0.88至0.99。