弱光信号周期误差对取样累积的影响分析

Effect analysis of the weak light periodic error on the sampling accumulation

在无同步信号参考的情况下,分析了弱光信号接收周期与发射周期存在误差时采用取样累积对信号检测输出信噪比的影响,通过计算发现随着累积次数的增加,输出信号的信噪比先增大然后减小,信号再次被噪声所淹没。针对以上问题,通过脉间累积与脉内累积的复合累积方法以及改变输出信噪比的计算方法,纠正了由于周期误差存在对取样累积的影响,利用实验数据计算表明,该方法使得输出信噪比与累积次数近似地呈线性增大关系。

The effect of the error between the weak light signal emission and receive period on the sampling accumulation output SNR（ signal to noise ratio） is analyzed under the condition of no synchronizing signal. By the calculation, the output SNR increases at first and then decreases with the increase of accumulation number,and the signal is covered by the noise at last. To solve this problem, a complex accumulation method contained the single pulse accumulation combined with the multiple pulse accumulation is used. The effect of the periodic error on the sampling accumulation is corrected. The experimental results show that the output SNR is approximately increased with the accumulation number linearly.