针对高重复频率相干测风激光雷达中风速反演时数据量大、计算量大、实时性要求高等问题提出了基于多核数字信号处理器(DSP)的并行风速反演算法。该算法的核心思想是, 利用高速数据处理板卡DSPC-8681上的4颗8核DSP处理器采用单指令多数据流的方式进行并行计算和同步, 使用最大似然离散谱峰值计算出视向风速。在激光脉冲重复频率为10 kHz的条件下实现了相干测风激光雷达中实时的风速反演。通过实验验证, 激光雷达的视向探测距离达到3 600 m, 距离分辨率为60 m, 风速测量范围为±30 m/s, 时间分辨率为1 s, 转动圆盘校准的速度测量精度优于0.48 m/s。

In order to solve the problems of huge volume backscattering signal data and time-consuming calculations when retrieving wind velocity in high repetition frequency coherent lidar, a parallel retrieval algorithm based on multicore Digital Signal Processor(DSP) was proposed. In this algorithm, a high performance DSPC-8681 card integrating four Texas Instruments(TI) TMS320C6678 processor with eight cores in each processor was employed. The digital data from Analog-to-Digital Convertor(ADC) was allocated equally to each core in each processor and processed in Single Instruction Multiply Data(SIMD) way. The wind velocity was retrieved by maximum likelihood discrete spectrum peak estimation. On the condition of 10 000 pulses accumulation, the time resolution of 1 s was realized. The performances of the developed coherent wind lidar are demonstrated by experiments, which are listed as follow: detection range in line of sight is 3 600 m; range resolution is 60 m; velocity range is ±30 m/s; time resolution is 1 s; velocity accuracy by rotating hard target is better than 0.48 m/s.