A series of flight experiments have demonstrated a novel approach to measuring path-resolved optical turbulence quantities, such as $C_n^2$, along an air-to-ground slant path. This paper describes the data acquisition experiments that involved two laser beams propagating between an orbiting airborne platform and a stationary ground terminal over an 8 km slant path. Ground-based and in-flight measurements were collected simultaneously, and $C_n^2$ profiles were computed using the difference of differential-tilt variance (DDTV) technique. This paper describes the DDTV technique that enables the path-resolved measurement of turbulence strength resulting in $C_n^2$ profiles. The resulting turbulence profiles reveal what is believed to be the aero-optical contamination from the aircraft boundary layer within the statistics closest to the aircraft. Therefore, the contamination of the aero-optical environment can be quantified with respect to the rest of the atmospheric propagation path. Lastly, this paper presents analyses that compare the measured atmospheric turbulence profiles to state-of-the-art atmospheric models. The analyses extend beyond $C_n^2$ comparisons and show the measurement-versus-modeling comparison in terms of key directed energy system propagation parameters such as Greenwood frequency, coherence diameter, Rytov number, isoplanatic angle, Tyler frequency, open-loop jitter, and open-loop Strehl ratio. The slant path turbulence is analyzed in the context of air-to-ground and ground-to-air directed energy systems.

一系列飞行实验证明了一种测量路径分辨光学湍流量的新方法，例如 $C_n^2$，沿空对地倾斜路径。本文描述了涉及两个激光束在轨道机载平台和固定地面终端之间通过 8 公里倾斜路径传播的数据采集实验。同时收集地面和飞行中的测量数据，并且$C_n^2$使用差异倾斜方差 (DDTV) 技术计算轮廓。本文介绍了 DDTV 技术，该技术能够对湍流强度进行路径分辨测量，从而导致$C_n^2$个人资料。由此产生的湍流剖面揭示了最接近飞机的统计数据中被认为是来自飞机边界层的航空光学污染。因此，可以相对于大气传播路径的其余部分对航空光学环境的污染进行量化。最后，本文介绍了将测量的大气湍流剖面与最先进的大气模型进行比较的分析。分析超出了$C_n^2$比较，并根据关键定向能量系统传播参数（例如格林伍德频率、相干直径、里托夫数、等距角、泰勒频率、开环抖动和开环斯特列尔比）显示测量与建模的比较。在空对地和地对空定向能量系统的背景下分析了倾斜路径湍流。