摘要
针对激光雨滴谱仪中接收端信号非常微弱、小雨滴信号容易受噪声干扰的特点,为提高系统的信噪比和小雨滴检测能力,基于微弱信号检测原理,优化前端模拟电路设计,采用数字锁相放大(DLIA)技术,构建了以OMAP3530的DSP Core为核心的数字锁相放大器。系统结构简单、易于实现,可以避免模拟器件的零漂、非线性等问题。仿真结果表明:这种数字锁相放大器能实现微弱信号的恒定放大,抑制了对带外噪声的放大,提高了信噪比(SNR),能有效提高激光雨滴谱仪的小雨滴检测能力。
Two problems affect the quality of the small raindrop measurement： the signals of small raindrops at the receiver of optical disdrometer are very weak; it is difficult to detect signals from a very noisy background. Based on the digital lock-in amplifier （DLIA） technique of weak signal detection principles, a digital lock-in amplifier with OMAP3530＇s DSP Core is constructed to solve the problems. The system is not only simple in structure, but also easy to implement. It can overcome zero-drift and none-linear in analog devices. Computer simulation results show that it can amplify weak signals constantly, inhibit the noise amplification of other frequency, and increase Signal to Noise Ratio （SNR）. It can improve the detection of small drops in optical disdrometer effectively.
出处
《气象科技》
2013年第4期603-607,613,共6页
Meteorological Science and Technology
