激光多普勒测速中的频谱校正及其应用

由于激光多普勒测速(LDA)系统的动态测试范围宽,信噪比低,单个散射粒子的渡越时间短,能采集到的信号长度有限,因此必须探索合适的频谱校正方法提高多普勒频率的精度来满足LDA的测量要求。将能量重心法、比值法、相位差法、频谱细化、频谱拟合等5种离散频谱校正方法应用于LDA信号处理中,通过仿真计算比较各种方法的优缺点,并选取比值法用于实时测量,取得了明显的效果。

Investigation on Frequency Correction Methods and Its Application in Digital Spectrum LDA Processor

With the development of digital signal processing technology, digital spectrum LDA processor are very interesting. Owing to low ratio of signal to noise, limited burst continuance and wide dynamic measurement range in LDA systems, spectrum correcting methods have to be studied in order to improve the precision of LDA processor. Energy centrobaric, ratio, zoom FFT, phase difference and spectrum simulation correcting methods are used in LDA signal processing. Through carrying out simulating calculation with three kinds of Doppler signals, ratio correcting method is picked out and applied in real-time measurement, and the satisfying result is achieved.