Numerical simulation for the detection of He density in thermosphere by resonant lidar
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摘要: 为了分析激光雷达探测热层氦浓度的回归信号和信噪比,采用理论分析和计算机模拟的方法,得到了峰值有效后向散射截面的数量级约为10-17M2的结果;在忽略背景噪声和考虑背景噪声的情况下,数值模拟研究了其回归信号的大小。结果表明,目前探测系统的信噪比是比较小的,要提高系统的信噪比,就要降低分辨率范围Δz和延长积分时间τ。这一结果对激光雷达探测热层氦浓度有帮助。Abstract: In order to analyze the back signals and the signal-noise-ratio for the detection of He density in thermosphere by means of resonant lidar,the effective backscattering cross-section of about 10-17m2 was obtained after computer simulation.The size of the back signal was analyzed through numerical simulation with neglecting and considering the background signal respectively.Results showed that the signal-noise-ratio for current system was low,and that the range of the resolving power Δz should be decreased and the integral time τ should be extended in order to improve the signal-noise-ratio.There results are helpful for the detection of He density in thermosphere by means of resonant lidar.
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