由于大气不稳定性以及光电探测器的各种噪声和天空背景辐射,使半导体激光云高仪APD探测器接收到 的后向散射信号信噪比较低,不能直接用于反演云层参数。所以针对后向散射信号的这种特点,提出 了一种基于FPGA的半导体激光云高仪数据采集处理实现方案。该方案能够实现后向散射信号隔直 流、高速采集、累积平均,与此同时还能完成整个系统发射、接收、数据存储和上传等复杂时 序控制。经实验对比验证,该方案能够明显提高后向散射信号信噪比、实现大气云层参数的反演。

Due to atmospheric instability, various noise and sky background radiation of photoelectric detector, the semiconductor laser ceilometer APD detector receives the backscatter signal with low signal noise ratio (SNR) which cannot be directly used for parameter inversion of cloud. So for this characteristic of the backward scattering signal, a data collection and processing scheme of the semiconductor laser ceilometer based on FPGA was proposed. This scheme can achieve the DC blocking of backward scattering signal, high-speed data acquisition, cumulative average, and at the same time it can complete complex sequential control, such as the whole system transmitting and receiving, data storage and upload. Compared with the experimental verification, the scheme can obviously increase the SNR of the backward scattering signal, and achieve the parameters inversion of atmospheric cloud.