Statistical analysis of measurements of atmospheric turbulence in different climates

Statistical analysis of measurements of atmospheric turbulence in different climates
复制标题

不同气候下大气湍流测量结果的统计分析

DOI：
10.1117/12.454395
复制
发表时间：
2002
期刊：
--
影响因子：
--
通讯作者：
L. S. Balfour
L. S. Balfour
中科院分区：
--
文献类型：
--
作者：
K. Weiss;L. S. Balfour

文献摘要

被引文献

相似文献

大气湍流可能会对远程告警传感器和其他光电系统的成像质量产生强烈影响。主要影响是光束展宽、强度波动(或闪烁)和到达角波动。折射率起伏的结构常数CN2是描述大气湍流强度最常用的参数。FGAN-FOM测量了两种不同气候下的CN2值，分别是中欧、德国的温和气候和以色列的干旱气候。干旱气候下的测量是与以色列海法Technion的EORD(电光研究与发展基金会)合作进行的。这些测量是用相同的激光闪烁仪沿着大约100米的水平光路进行的，在欧洲中部的草原上，在以色列没有植被的石质地面上。连续收集数据至少一年，每次分辨率为5分钟。对于这两种气候，都给出了CN2日循环的例子。由于CN2通常作为一天中的时间和季节的函数变化，其对光电系统的影响只能以统计方式表示。因此，计算了两种气候在一个月的时间段内CN2的累积发生频率。这些结果被用来计算典型的红外传感器的湍流调制传递函数(MTF)和点扩展函数(PSF)，该传感器带有碲镉汞探测器(CMT)和UV传感器。
Atmospheric turbulence may have a strong impact on the imaging quality of long range warning sensors and other electro-optical systems. Major effects are beam broadening, intensity fluctuations (or scintillation) and angle-of- arrival fluctuations. The structure constant of refractive index fluctuations, Cn2, is the parameter most commonly used to describe the strength of atmospheric turbulence. FGAN-FOM measured Cn2 values in two different climates, moderate climate in mid-Europe, Germany and arid climate in Israel. The measurements in arid climate were carried out in cooperation with the EORD (Electro-Optics Research & Development Foundation Ltd.), TECHNION, Haifa, Israel. The measurements were performed with identical laser scintillometers along a horizontal optical path of about 100 m, above grassland in mid-Europe, and above stony ground without vegetation in Israel. The data were collected continuously for a time period of at least one year at a time resolution of 5 minutes. For both climates examples of the diurnal cycle of Cn2 are given. Since Cn2 usually changes as a function of time-of-day and of season its influence on electro-optical systems can only be expressed in a statistical way. Therefore the cumulative frequencies of occurrence of Cn2 were calculated for a time period of one month for both climates. These results were used to calculate the corresponding turbulence modulation transfer function (MTF) and point spread function (PSF) for a typical IR sensor with a Cadmium Mercury Telluride detector (CMT) and a UV sensor.