单光子计数技术是利用光电倍增管探测微弱光信号的一种有效方法,广泛应用于航空领域的激光雷达探测。针对激光雷达回波信号强度弱、数据量大、实时要求高等特点,设计了基于FPGA芯片的高速数据采集系统。该系统利用光电倍增管精确探测微弱的雷达回波信号,两个光子计数器通过乒乓操作实现了无时间间隙的计数采集,利用存储控制器和传输控制器对外围芯片进行控制,实现了对采集数据的实时缓存和高速传输。为验证采集系统的有效性,将其应用于米散射微脉冲激光雷达,实现7.5 km的有效探测,探测精度为7.5 m。在此基础上,将采集系统与EASY-MCS光子计数器的测量结果进行对比,其均方误差为8%,表明本系统具有良好的准确性和稳定性,可满足激光雷达对微弱回波信号采集的要求,在航空气象探测领域具有广阔的应用前景。

The single photon counting technique is an effective method for detecting weak optical signals by using a photomultiplier tube, which is widely used in lidar detection in the area of aviation.Considering that lidar echo signals have such characteristics as weak strength, large data volume and high real-time requirements, we designed a high-speed data acquisition system based on the FPGA chip.The system accurately detects the weak lidar echo signal by using the photomultiplier tube, and the counting collection without time intervals is realized through the ping-pong operation by using two photon counters.Storage controllers and transmission controllers are used to control the peripheral chips.In this way, the real-time caching and high-speed transmission of the acquired data are realized.In order to verify the effectiveness of the proposed system, it was applied to the mie-scattering micro-pluse lidar and realized an effective detection of 7.5 km with a detection accuracy of 7.5 m.On this basis, a comparison was made to the measurement results of the acquisition system and the EASY-MCS photon counter.The mean square error was 8%.It indicates that the proposed system has high accuracy and stability, and can meet the requirements of weak echo signal acquisition of the lidar, which will have broad application prospects in the field of aviation meteorological detection.