Schwiesow R L, Cupp R E
Appl Opt. 1980 Sep 15;19(18):3168-72. doi: 10.1364/AO.19.003168.
A moving scattering target used as a transfer standard allows absolute calibration of the response of a cw Doppler lidar to an atmospheric target. The lidar in this study operated at a 10.6-microm wavelength. Consideration of the distribution of radiant energy density near the focus of the lidar transceiver permits measurement of a backscatter coefficient from a distributed array of scatterers, such as atmospheric aerosols, based on the diffuse reflectance of the surface of the transfer standard. The minimum detectable signal for our system with a 5-sec averaging time corresponds to a backscatter coefficient of 2.4 x 10(-12) m (-1) sr (-1) +/- 2.5 dB, which is ~ 9 dB greater than the theoretical threshold. Calibration shows that the lidar response is 5+/-1 dB less than the ideal limit for signal powers well above the minimum detectable signal.
用作传递标准的移动散射靶可实现连续波多普勒激光雷达对大气目标响应的绝对校准。本研究中的激光雷达工作波长为10.6微米。考虑激光雷达收发器焦点附近的辐射能量密度分布，基于传递标准表面的漫反射率，可测量来自诸如大气气溶胶等散射体分布式阵列的后向散射系数。我们系统在5秒平均时间下的最小可探测信号对应于2.4×10⁻¹²米⁻¹球面度⁻¹的后向散射系数±2.5分贝，这比理论阈值大~9分贝。校准表明，对于远高于最小可探测信号的信号功率，激光雷达响应比理想极限低5±1分贝。
