基于宽频带温度脉动仪的大气温度起伏谱测量

Measurements of the spectrum of atmospheric temperature fluctuations based on broadband micro-temperature sensor

常用温度脉动仪测量湍流的频谱,频谱范围多在20Hz以下,无法呈现大气温度起伏的高频特征。介绍一种宽频带低噪声温度脉动仪的设计方法,研制出相应的仪器,并进行了真实大气温度起伏测量实验。结果表明,大气温度起伏具有丰富的高频信息,温度起伏功率谱在更宽的频率范围内存在幂率不变性,部分温度谱在高频部分出现拐点,以更陡的幂率下降,湍流谱的形状以及拐点出现的位置和湍流强度有一定的关系。拓宽了温度起伏功率谱的研究范围,为光波传输的理论研究和技术应用提供了高频湍流谱信息,为非Kolmogorov湍流研究提供了测量手段。

The frequency spectrum of turbulence measured by common micro-temperature sensor is mostly below 20 Hz, which can not show the high frequency characteristics of atmospheric temperature fluctuation.This paper introduces the design of a broadband low noise micro-temperature sensor, the development of the corresponding instrument, and the real atmospheric temperature fluctuation measurement experiment. It is shown that the atmospheric temperature fluctuation has abundant high frequency information. The power spectrum of temperature fluctuation has power invariance in a wider frequency range. Some of the temperature spectrum has inflection points in the high frequency part, and decreases more steeply. The shape of the turbulence spectrum and the position of the inflection point are related to the turbulence intensity. This study broadens the research scope of temperature fluctuation power spectrum, provides high frequency turbulence spectrum information for theoretical research and technical application of light wave transmission, and provides measurements for non-Kolmogorov turbulence research.