Several critical qualifications in measurement ofatmospheric coherence length
摘要: 为规范大气相干长度的测量，保证测量数据的准确性，通过对大气相干长度测量中采样频率、采样时长、曝光时间等关键问题的分析，并结合国内外相关研究成果，确定了差分像运动测量仪的采样频率应不低于100 Hz、采样时长应不短于20 s ，单帧图像曝光时间应不长于沿测量光路的格林伍德时间常数，样本数应不少于2 000帧。Abstract: In order to ensure the accuracy in measurement of atmospheric coherence length, it is necessary to specify qualifications of measurement. The qualifications of differential image motion monitor are determined through analysis of several critical problems such as sampring frequency, spampling time and exposure time in measurement of atmospheric coherence length, and combining with the result of domestic and foreign research, it is ensured that the sampling frequency should not be lower than 100 Hz, the sampling time should not be shorter than 20 s, the exposure time of single frame image should not be longer than the Greenwood time constant along with the measuring beam path, and the number of samples should not be less than 2 000 frames.
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